feat: persist handled activity session watermarks

frontend/src/App.svelte

@@ -54,6 +54,7 @@
     const name = workspaceName(workspace);
     return {
       id: name,
+      workspaceId: workspace?.id || workspace?.workspaceId || '',
       type: workspace?.type || 'space',
       title: workspace?.title || name,
       name,

frontend/src/lib/plugin-host/VerstakPluginAPI.js

@@ -262,6 +262,26 @@ export function createPluginAPI(pluginId) {
             return data || {};
           });
         },
+        readNDJSON: function(name) {
+          assertActive('storage.data.readNDJSON(' + name + ')');
+          if (!name) {
+            throw new Error('storage.data.readNDJSON requires a name');
+          }
+          return callBackend(pluginId, 'storage.data.readNDJSON(' + name + ')', function() {
+            return App.ReadPluginDataNDJSON(pluginId, name);
+          }).then(function(records) {
+            return Array.isArray(records) ? records : [];
+          });
+        },
+        writeNDJSON: function(name, records) {
+          assertActive('storage.data.writeNDJSON(' + name + ')');
+          if (!name) {
+            throw new Error('storage.data.writeNDJSON requires a name');
+          }
+          return callBackendErrorString(pluginId, 'storage.data.writeNDJSON(' + name + ')', function() {
+            return App.WritePluginDataNDJSON(pluginId, name, Array.isArray(records) ? records : []);
+          });
+        },
         write: function(name, data) {
           assertActive('storage.data.write(' + name + ')');
           if (!name) {
@@ -409,6 +429,12 @@ export function createPluginAPI(pluginId) {
           return App.OpenVaultPathExternal(pluginId, relativePath);
         });
       },
+      openURL: function(url) {
+        assertActive('files.openURL');
+        return callBackendErrorString(pluginId, 'files.openURL', function() {
+          return App.OpenExternalURL(pluginId, String(url == null ? '' : url));
+        });
+      },
       showInFolder: function(relativePath) {
         assertActive('files.showInFolder(' + relativePath + ')');
         return callBackendErrorString(pluginId, 'files.showInFolder(' + relativePath + ')', function() {

frontend/src/lib/shell/WorkspaceHost.svelte

@@ -43,6 +43,7 @@
 
   $: selectedWorkspace = nodes.find(n => n.id === selectedWorkspaceName || n.name === selectedWorkspaceName || n.rootPath === selectedWorkspaceName) || null;
   $: workspaceRootPath = selectedWorkspace?.rootPath || selectedWorkspace?.name || selectedWorkspace?.id || '';
+  $: workspaceId = selectedWorkspace?.workspaceId || '';
   $: workspaceTitle = selectedWorkspace?.title || selectedWorkspace?.name || selectedWorkspace?.id || selectedWorkspaceName;
   $: workspaceType = selectedWorkspace?.type || 'workspace';
   $: if (workspaceRootPath !== metadataWorkspaceRoot) {
@@ -235,7 +236,7 @@
             <PluginBundleHost
               pluginId={activeTool.pluginId}
               componentId={activeTool.component}
-              componentProps={{ workspaceName: selectedWorkspaceName, workspaceNodeId: selectedWorkspaceName, workspaceNode: selectedWorkspace, workspaceRootPath, toolRequest: activeToolRequest }}
+              componentProps={{ workspaceName: selectedWorkspaceName, workspaceNodeId: selectedWorkspaceName, workspaceNode: selectedWorkspace, workspaceRootPath, workspaceId, toolRequest: activeToolRequest }}
             />
           {/if}
         {/if}

frontend/src/lib/test/wails-mock.js

@@ -3341,11 +3341,20 @@
       var data = (pluginData[pluginId] && pluginData[pluginId][name]) || {};
       return Promise.resolve([Object.assign({}, data), '']);
     },
+    ReadPluginDataNDJSON: function (pluginId, name) {
+      var data = (pluginData[pluginId] && pluginData[pluginId][name]) || [];
+      return Promise.resolve([Array.isArray(data) ? data.slice() : [], '']);
+    },
     WritePluginDataJSON: function (pluginId, name, data) {
       pluginData[pluginId] = pluginData[pluginId] || {};
       pluginData[pluginId][name] = Object.assign({}, data || {});
       return Promise.resolve('');
     },
+    WritePluginDataNDJSON: function (pluginId, name, records) {
+      pluginData[pluginId] = pluginData[pluginId] || {};
+      pluginData[pluginId][name] = Array.isArray(records) ? records.slice() : [];
+      return Promise.resolve('');
+    },
     OpenWorkbenchResource: function (pluginId, request) {
       return openWorkbenchResource(pluginId, request || {}, '');
     },
@@ -3678,6 +3687,13 @@
       window.__wailsMockExternalOpens = externalOpens.slice();
       return Promise.resolve('');
     },
+    OpenExternalURL: function (pluginId, rawURL) {
+      var err = requirePluginPermission(pluginId, 'files.openExternal');
+      if (err) return Promise.resolve(err);
+      externalOpens.push({ action: 'url', path: String(rawURL || '') });
+      window.__wailsMockExternalOpens = externalOpens.slice();
+      return Promise.resolve('');
+    },
     ShowVaultPathInFolder: function (pluginId, relativePath) {
       var err = requirePluginPermission(pluginId, 'files.openExternal');
       if (err) return Promise.resolve(err);

frontend/wailsjs/go/api/App.d.ts

@@ -74,6 +74,8 @@ export function ListVaultTrash(arg1:string):Promise<Array<files.TrashEntry>|stri
 
 export function ListWorkspaces():Promise<Array<workspace.Workspace>|string>;
 
+export function ListWorkspaceIdentities():Promise<Array<workspace.WorkspaceIdentity>|string>;
+
 export function ListWorkspaceTemplates():Promise<Array<workspace.WorkspaceTemplate>|string>;
 
 export function MoveVaultPath(arg1:string,arg2:string,arg3:string,arg4:files.MoveOptions):Promise<string>;
@@ -84,6 +86,8 @@ export function OpenVault(arg1:string):Promise<void>;
 
 export function OpenVaultPathExternal(arg1:string,arg2:string):Promise<string>;
 
+export function OpenExternalURL(arg1:string,arg2:string):Promise<string>;
+
 export function OpenWorkbenchResource(arg1:string,arg2:Record<string, any>):Promise<workbench.OpenResourceResult|string>;
 
 export function PluginBrowserReceiverPairing(arg1:string):Promise<Record<string, string>|string>;
@@ -122,6 +126,8 @@ export function PublishPluginEvent(arg1:string,arg2:string,arg3:Record<string, a
 
 export function ReadPluginDataJSON(arg1:string,arg2:string):Promise<Record<string, any>>;
 
+export function ReadPluginDataNDJSON(arg1:string,arg2:string):Promise<Array<Record<string, any>>>;
+
 export function ReadPluginSetting(arg1:string,arg2:string):Promise<any>;
 
 export function ReadPluginSettings(arg1:string):Promise<Record<string, any>|string>;
@@ -136,12 +142,18 @@ export function ReloadPlugins():Promise<number|string>;
 
 export function RenameWorkspace(arg1:string,arg2:string):Promise<string>;
 
+export function RepairWorkspaceIdentity(arg1:string,arg2:string):Promise<string>;
+
 export function RenameWorkspaceNode(arg1:string,arg2:string):Promise<string>;
 
 export function RestoreVaultTrash(arg1:string,arg2:string,arg3:files.RestoreOptions):Promise<string|string>;
 
+export function RestoreWorkspaceTrash(arg1:string,arg2:string):Promise<workspace.Workspace|string>;
+
 export function SelectDirectory():Promise<string>;
 
+export function PurgeWorkspaceTrash(arg1:string):Promise<string>;
+
 export function SelectVaultForOpen():Promise<string>;
 
 export function SetCurrentVault(arg1:string):Promise<string>;
@@ -168,6 +180,8 @@ export function WriteFrontendLog(arg1:string,arg2:string):Promise<void>;
 
 export function WritePluginDataJSON(arg1:string,arg2:string,arg3:Record<string, any>):Promise<string>;
 
+export function WritePluginDataNDJSON(arg1:string,arg2:string,arg3:Array<Record<string, any>>):Promise<string>;
+
 export function WritePluginSetting(arg1:string,arg2:string,arg3:any):Promise<string>;
 
 export function WritePluginSettings(arg1:string,arg2:Record<string, any>):Promise<string>;

frontend/wailsjs/go/api/App.js

@@ -134,6 +134,10 @@ export function ListWorkspaces() {
   return window['go']['api']['App']['ListWorkspaces']();
 }
 
+export function ListWorkspaceIdentities() {
+  return window['go']['api']['App']['ListWorkspaceIdentities']();
+}
+
 export function ListWorkspaceTemplates() {
   return window['go']['api']['App']['ListWorkspaceTemplates']();
 }
@@ -154,6 +158,10 @@ export function OpenVaultPathExternal(arg1, arg2) {
   return window['go']['api']['App']['OpenVaultPathExternal'](arg1, arg2);
 }
 
+export function OpenExternalURL(arg1, arg2) {
+  return window['go']['api']['App']['OpenExternalURL'](arg1, arg2);
+}
+
 export function OpenWorkbenchResource(arg1, arg2) {
   return window['go']['api']['App']['OpenWorkbenchResource'](arg1, arg2);
 }
@@ -230,6 +238,10 @@ export function ReadPluginDataJSON(arg1, arg2) {
   return window['go']['api']['App']['ReadPluginDataJSON'](arg1, arg2);
 }
 
+export function ReadPluginDataNDJSON(arg1, arg2) {
+  return window['go']['api']['App']['ReadPluginDataNDJSON'](arg1, arg2);
+}
+
 export function ReadPluginSetting(arg1, arg2) {
   return window['go']['api']['App']['ReadPluginSetting'](arg1, arg2);
 }
@@ -258,6 +270,10 @@ export function RenameWorkspace(arg1, arg2) {
   return window['go']['api']['App']['RenameWorkspace'](arg1, arg2);
 }
 
+export function RepairWorkspaceIdentity(arg1, arg2) {
+  return window['go']['api']['App']['RepairWorkspaceIdentity'](arg1, arg2);
+}
+
 export function RenameWorkspaceNode(arg1, arg2) {
   return window['go']['api']['App']['RenameWorkspaceNode'](arg1, arg2);
 }
@@ -266,10 +282,18 @@ export function RestoreVaultTrash(arg1, arg2, arg3) {
   return window['go']['api']['App']['RestoreVaultTrash'](arg1, arg2, arg3);
 }
 
+export function RestoreWorkspaceTrash(arg1, arg2) {
+  return window['go']['api']['App']['RestoreWorkspaceTrash'](arg1, arg2);
+}
+
 export function SelectDirectory() {
   return window['go']['api']['App']['SelectDirectory']();
 }
 
+export function PurgeWorkspaceTrash(arg1) {
+  return window['go']['api']['App']['PurgeWorkspaceTrash'](arg1);
+}
+
 export function SelectVaultForOpen() {
   return window['go']['api']['App']['SelectVaultForOpen']();
 }
@@ -322,6 +346,10 @@ export function WritePluginDataJSON(arg1, arg2, arg3) {
   return window['go']['api']['App']['WritePluginDataJSON'](arg1, arg2, arg3);
 }
 
+export function WritePluginDataNDJSON(arg1, arg2, arg3) {
+  return window['go']['api']['App']['WritePluginDataNDJSON'](arg1, arg2, arg3);
+}
+
 export function WritePluginSetting(arg1, arg2, arg3) {
   return window['go']['api']['App']['WritePluginSetting'](arg1, arg2, arg3);
 }

frontend/wailsjs/go/models.ts

@@ -1272,6 +1272,7 @@ export namespace workspace {
 	    }
 	}
 	export class Metadata {
+	    workspaceId?: string;
 	    workspaceName: string;
 	    createdFromTemplate?: TemplateSnapshot;
 	    features?: Record<string, boolean>;
@@ -1285,6 +1286,7 @@ export namespace workspace {
 	
 	    constructor(source: any = {}) {
 	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.workspaceId = source["workspaceId"];
 	        this.workspaceName = source["workspaceName"];
 	        this.createdFromTemplate = this.convertValues(source["createdFromTemplate"], TemplateSnapshot);
 	        this.features = source["features"];
@@ -1327,6 +1329,7 @@ export namespace workspace {
 	}
 	
 	export class TrashResult {
+	    workspaceId: string;
 	    originalPath: string;
 	    trashPath: string;
 	    trashId: string;
@@ -1338,6 +1341,7 @@ export namespace workspace {
 	
 	    constructor(source: any = {}) {
 	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.workspaceId = source["workspaceId"];
 	        this.originalPath = source["originalPath"];
 	        this.trashPath = source["trashPath"];
 	        this.trashId = source["trashId"];
@@ -1345,6 +1349,7 @@ export namespace workspace {
 	    }
 	}
 	export class Workspace {
+	    id: string;
 	    name: string;
 	    rootPath: string;
 	
@@ -1354,9 +1359,27 @@ export namespace workspace {
 	
 	    constructor(source: any = {}) {
 	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.id = source["id"];
 	        this.name = source["name"];
 	        this.rootPath = source["rootPath"];
 	    }
 	}
 
+	export class WorkspaceIdentity {
+	    workspaceId: string;
+	    rootPath: string;
+	    state: string;
+
+	    static createFrom(source: any = {}) {
+	        return new WorkspaceIdentity(source);
+	    }
+
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.workspaceId = source["workspaceId"];
+	        this.rootPath = source["rootPath"];
+	        this.state = source["state"];
+	    }
+	}
+
 }

go.mod

@@ -5,6 +5,7 @@ go 1.24.4
 require (
 	github.com/google/uuid v1.6.0
 	github.com/wailsapp/wails/v2 v2.12.0
+	golang.org/x/net v0.35.0
 )
 
 require (
@@ -32,7 +33,6 @@ require (
 	github.com/wailsapp/go-webview2 v1.0.22 // indirect
 	github.com/wailsapp/mimetype v1.4.1 // indirect
 	golang.org/x/crypto v0.33.0 // indirect
-	golang.org/x/net v0.35.0 // indirect
 	golang.org/x/sys v0.30.0 // indirect
 	golang.org/x/text v0.22.0 // indirect
 )

internal/api/app.go

@@ -40,9 +40,13 @@ var newSyncClient = syncsvc.NewClient
 var emitFrontendEvent = runtime.EventsEmit
 
 const pluginEventRuntimeName = "verstak:plugin-event"
-const activityGlobalKey = "events:global"
+const activityPluginID = "verstak.activity"
-const activityWorkspacePrefix = "events:workspace:"
+const activityRawDataName = "activity-events"
-const maxActivityEvents = 250
+const activitySessionHandlingKey = "activity-session-handling-v2"
+const activitySessionHandledEvent = "activity.session.handled"
+const maxActivityRawEvents = 10000
+const maxActivityRawBytes = 8 * 1024 * 1024
+const activityRetention = 60 * 24 * time.Hour
 const browserInboxPluginID = "verstak.browser-inbox"
 const browserInboxGlobalKey = "captures:global"
 const browserInboxLegacyKey = "captures"
@@ -52,6 +56,8 @@ const maxBrowserInboxCaptures = 100
 const workspaceCreatedEventName = "workspace.created"
 const workspaceRenamedEventName = "workspace.renamed"
 const workspaceTrashedEventName = "workspace.trashed"
+const workspaceRestoredEventName = "workspace.restored"
+const workspacePurgedEventName = "workspace.purged"
 const workspaceSelectedEventName = "workspace.selected"
 
 // App is the main application struct exposed to the Wails frontend.
@@ -130,6 +136,7 @@ func NewApp(
 	app.ensureBrowserInboxSubscriptions()
 	if app.browserReceiver != nil {
 		app.browserReceiver.SetPersistence(app.browserInboxAvailable, app.recordBrowserCapture)
+		app.browserReceiver.SetActivityPersistence(app.activityAvailable, app.recordBrowserActivityBatch)
 	}
 	app.startFileWatcherForOpenVault()
 	return app
@@ -183,15 +190,21 @@ func (a *App) ensureBrowserInboxSubscriptions() {
 	if a.browserInboxEvents == nil {
 		a.browserInboxEvents = make(map[string]bool)
 	}
-	for _, eventName := range []string{browserInboxMutationEvent} {
+	for _, eventName := range []string{browserInboxMutationEvent, workspaceRenamedEventName, workspaceTrashedEventName, workspaceRestoredEventName, workspacePurgedEventName} {
 		if a.browserInboxEvents[eventName] {
 			continue
 		}
 		a.browserInboxEvents[eventName] = true
 		a.eventBus.Subscribe(eventName, func(event events.Event) {
+			if event.Name == browserInboxMutationEvent {
 				if err := a.mutateBrowserInboxCapture(event); err != nil {
 					log.Printf("[api] browser inbox mutation failed: %v", err)
 				}
+				return
+			}
+			if err := a.updateBrowserInboxWorkspaceLifecycle(event); err != nil {
+				log.Printf("[api] browser inbox workspace lifecycle failed: %v", err)
+			}
 		})
 	}
 }
@@ -203,6 +216,78 @@ func (a *App) browserInboxAvailable() bool {
 	return true
 }
 
+func (a *App) activityAvailable() bool {
+	if a == nil || a.storage == nil || a.vault == nil || a.vault.GetVaultStatus() != vault.StatusOpen {
+		return false
+	}
+	_, err := a.requirePluginAccess(activityPluginID, "storage.namespace")
+	return err == nil
+}
+
+func (a *App) recordBrowserActivityBatch(event events.Event) error {
+	if !a.activityAvailable() {
+		return fmt.Errorf("activity storage unavailable")
+	}
+	payload := eventPayloadMap(event.Payload)
+	batchID := firstPayloadText(payload, "batchId")
+	if batchID == "" {
+		return fmt.Errorf("batchId is empty")
+	}
+	entries, ok := payload["entries"].([]map[string]interface{})
+	if !ok || len(entries) == 0 {
+		return fmt.Errorf("activity batch entries are empty")
+	}
+	now := time.Now().UTC().Format(time.RFC3339Nano)
+	receivedAt := event.Timestamp
+	if receivedAt == "" {
+		receivedAt = now
+	}
+	records := make([]map[string]interface{}, 0, len(entries))
+	for index, entry := range entries {
+		hostname := firstPayloadText(entry, "hostname")
+		endedAt := firstPayloadText(entry, "endedAt")
+		if hostname == "" || endedAt == "" {
+			return fmt.Errorf("activity batch entry %d is invalid", index)
+		}
+		durationSeconds, _ := entry["durationSeconds"].(int64)
+		if durationSeconds == 0 {
+			if number, ok := entry["durationSeconds"].(float64); ok {
+				durationSeconds = int64(number)
+			}
+		}
+		records = append(records, map[string]interface{}{
+			"activityId":        fmt.Sprintf("browser-domain:%s:%d", batchID, index),
+			"type":              "browser.activity.domain",
+			"title":             hostname,
+			"summary":           fmt.Sprintf("%d min browser activity", durationSeconds/60),
+			"occurredAt":        endedAt,
+			"receivedAt":        receivedAt,
+			"sourcePluginId":    "verstak-browser-extension",
+			"sourceBatchId":     batchID,
+			"hostname":          hostname,
+			"startedAt":         firstPayloadText(entry, "startedAt"),
+			"endedAt":           endedAt,
+			"durationSeconds":   durationSeconds,
+			"workspaceRootPath": "",
+			"payload": map[string]interface{}{
+				"hostname":        hostname,
+				"startedAt":       firstPayloadText(entry, "startedAt"),
+				"endedAt":         endedAt,
+				"durationSeconds": durationSeconds,
+			},
+		})
+	}
+	_, err := a.storage.AppendPluginDataNDJSON(activityPluginID, activityRawDataName, records, storage.NDJSONRetention{
+		TimestampField:   "occurredAt",
+		MaxAge:           activityRetention,
+		MaxEntries:       maxActivityRawEvents,
+		MaxBytes:         maxActivityRawBytes,
+		DeduplicateField: "sourceBatchId",
+		DeduplicateValue: batchID,
+	})
+	return err
+}
+
 func (a *App) recordBrowserCapture(event events.Event) error {
 	if !a.browserInboxAvailable() {
 		return fmt.Errorf("browser inbox unavailable")
@@ -218,6 +303,10 @@ func (a *App) recordBrowserCapture(event events.Event) error {
 	if firstPayloadText(capture, "capturedAt") == "" {
 		capture["capturedAt"] = event.Timestamp
 	}
+	if firstPayloadText(capture, "globalState") == "" {
+		capture["globalState"] = "inbox"
+	}
+	a.annotateBrowserCaptureWorkspace(capture)
 	capture["receivedAt"] = time.Now().UTC().Format(time.RFC3339Nano)
 	return a.updateBrowserInboxCaptures(func(captures []map[string]interface{}) []map[string]interface{} {
 		for _, stored := range captures {
@@ -238,7 +327,7 @@ func (a *App) mutateBrowserInboxCapture(event events.Event) error {
 	}
 	action := firstPayloadText(payload, "action")
 	switch action {
-	case "migrate", "assign", "delete", "processed":
+	case "migrate", "assign", "archive", "restore", "delete", "processed":
 	default:
 		return fmt.Errorf("unsupported browser inbox mutation %q", action)
 	}
@@ -268,10 +357,17 @@ func (a *App) mutateBrowserInboxCapture(event events.Event) error {
 			switch action {
 			case "delete":
 				continue
+			case "archive":
+				capture["globalState"] = "archived"
+			case "restore":
+				capture["globalState"] = "inbox"
 			case "assign":
 				workspaceRoot := firstPayloadText(payload, "workspaceRootPath")
 				capture["workspaceRootPath"] = workspaceRoot
 				capture["workspaceName"] = workspaceRoot
+				delete(capture, "workspaceId")
+				delete(capture, "workspaceTrashId")
+				a.annotateBrowserCaptureWorkspace(capture)
 			case "processed":
 				capture["processed"], _ = payload["processed"].(bool)
 			}
@@ -281,6 +377,67 @@ func (a *App) mutateBrowserInboxCapture(event events.Event) error {
 	})
 }
 
+func (a *App) annotateBrowserCaptureWorkspace(capture map[string]interface{}) {
+	if capture == nil {
+		return
+	}
+	workspaceRoot := firstPayloadText(capture, "workspaceRootPath")
+	if workspaceRoot == "" {
+		capture["workspaceState"] = "unassigned"
+		delete(capture, "workspaceId")
+		delete(capture, "workspaceTrashId")
+		return
+	}
+	if firstPayloadText(capture, "workspaceId") != "" {
+		if firstPayloadText(capture, "workspaceState") == "" {
+			capture["workspaceState"] = "active"
+		}
+		return
+	}
+	if a.workspace == nil {
+		capture["workspaceState"] = "unavailable"
+		return
+	}
+	identity, err := a.workspace.GetWorkspaceIdentity(workspaceRoot)
+	if err != nil {
+		capture["workspaceState"] = "unavailable"
+		return
+	}
+	capture["workspaceId"] = identity.WorkspaceID
+	capture["workspaceRootPath"] = identity.RootPath
+	capture["workspaceName"] = identity.RootPath
+	capture["workspaceState"] = identity.State
+}
+
+func (a *App) updateBrowserInboxWorkspaceLifecycle(event events.Event) error {
+	payload := eventPayloadMap(event.Payload)
+	workspaceID := firstPayloadText(payload, "workspaceId")
+	if workspaceID == "" {
+		return nil
+	}
+	return a.updateBrowserInboxCaptures(func(captures []map[string]interface{}) []map[string]interface{} {
+		for _, capture := range captures {
+			if firstPayloadText(capture, "workspaceId") != workspaceID {
+				continue
+			}
+			switch event.Name {
+			case workspaceRenamedEventName, workspaceRestoredEventName:
+				capture["workspaceRootPath"] = firstPayloadText(payload, "workspaceRootPath")
+				capture["workspaceName"] = firstPayloadText(payload, "workspaceName", "workspaceRootPath")
+				capture["workspaceState"] = "active"
+				delete(capture, "workspaceTrashId")
+			case workspaceTrashedEventName:
+				capture["workspaceState"] = "trashed"
+				capture["workspaceTrashId"] = firstPayloadText(payload, "trashId")
+			case workspacePurgedEventName:
+				capture["workspaceState"] = "orphaned"
+				delete(capture, "workspaceTrashId")
+			}
+		}
+		return captures
+	})
+}
+
 func (a *App) updateBrowserInboxCaptures(update func([]map[string]interface{}) []map[string]interface{}) error {
 	if !a.browserInboxAvailable() {
 		return fmt.Errorf("browser inbox unavailable")
@@ -334,6 +491,9 @@ func browserInboxCaptures(settings map[string]interface{}) ([]map[string]interfa
 				continue
 			}
 			seen[captureID] = true
+			if firstPayloadText(capture, "globalState") == "" {
+				capture["globalState"] = "inbox"
+			}
 			if firstPayloadText(capture, "workspaceRootPath") == "" && workspaceRoot != "" {
 				capture["workspaceRootPath"] = workspaceRoot
 				capture["workspaceName"] = workspaceRoot
@@ -406,6 +566,46 @@ func (a *App) ensureActivityProviderSubscriptions() {
 			})
 		}
 	}
+	if !a.activityEvents[activitySessionHandledEvent] {
+		a.activityEvents[activitySessionHandledEvent] = true
+		a.eventBus.Subscribe(activitySessionHandledEvent, func(event events.Event) {
+			if err := a.recordActivitySessionHandled(event); err != nil {
+				log.Printf("[api] activity session handling update failed: %v", err)
+			}
+		})
+	}
+}
+
+func (a *App) recordActivitySessionHandled(event events.Event) error {
+	if !a.activityAvailable() {
+		return fmt.Errorf("activity storage unavailable")
+	}
+	payload := eventPayloadMap(event.Payload)
+	if firstPayloadText(payload, "pluginId") != "verstak.journal" {
+		return fmt.Errorf("activity session handling source is not authorized")
+	}
+	sessionID := firstPayloadText(payload, "sessionId")
+	handledThrough := firstPayloadText(payload, "handledThrough")
+	status := firstPayloadText(payload, "status")
+	if sessionID == "" || handledThrough == "" || (status != "accepted" && status != "dismissed") {
+		return fmt.Errorf("activity session handling payload is invalid")
+	}
+	if _, err := time.Parse(time.RFC3339, handledThrough); err != nil {
+		return fmt.Errorf("activity session handledThrough is invalid")
+	}
+	return a.storage.UpdatePluginSettings(activityPluginID, func(settings map[string]interface{}) error {
+		handled, _ := settings[activitySessionHandlingKey].(map[string]interface{})
+		if handled == nil {
+			handled = make(map[string]interface{})
+		}
+		handled[sessionID] = map[string]interface{}{
+			"status":         status,
+			"handledThrough": handledThrough,
+			"handledAt":      time.Now().UTC().Format(time.RFC3339Nano),
+		}
+		settings[activitySessionHandlingKey] = handled
+		return nil
+	})
 }
 
 func (a *App) recordActivityProviderEvent(event events.Event) {
@@ -419,35 +619,20 @@ func (a *App) recordActivityProviderEvent(event events.Event) {
 		if _, err := a.requirePluginAccess(provider.PluginID, "storage.namespace"); err != nil {
 			continue
 		}
-		if err := a.appendActivityEvent(provider.PluginID, activityFromEvent(event)); err != nil {
+		if err := a.appendActivityEvent(provider.PluginID, a.activityFromEvent(event)); err != nil {
 			log.Printf("[api] activity provider %s failed to record %s: %v", provider.PluginID, event.Name, err)
 		}
 	}
 }
 
 func (a *App) appendActivityEvent(pluginID string, activity map[string]interface{}) error {
-	settings, err := a.storage.ReadPluginSettings(pluginID)
+	_, err := a.storage.AppendPluginDataNDJSON(pluginID, activityRawDataName, []map[string]interface{}{activity}, storage.NDJSONRetention{
-	if err != nil {
+		TimestampField: "occurredAt",
+		MaxAge:         activityRetention,
+		MaxEntries:     maxActivityRawEvents,
+		MaxBytes:       maxActivityRawBytes,
+	})
 	return err
-	}
-	key := activityGlobalKey
-	if workspace, _ := activity["workspaceRootPath"].(string); strings.TrimSpace(workspace) != "" {
-		key = activityWorkspacePrefix + url.QueryEscape(strings.TrimSpace(workspace))
-		key = strings.ReplaceAll(key, "+", "%20")
-	}
-	eventsList := []interface{}{activity}
-	if existing, ok := settings[key].([]interface{}); ok {
-		eventsList = append(eventsList, existing...)
-	} else if existingMaps, ok := settings[key].([]map[string]interface{}); ok {
-		for _, item := range existingMaps {
-			eventsList = append(eventsList, item)
-		}
-	}
-	if len(eventsList) > maxActivityEvents {
-		eventsList = eventsList[:maxActivityEvents]
-	}
-	settings[key] = eventsList
-	return a.storage.WritePluginSettings(pluginID, settings)
 }
 
 func activityFromEvent(event events.Event) map[string]interface{} {
@@ -479,6 +664,24 @@ func activityFromEvent(event events.Event) map[string]interface{} {
 	}
 }
 
+func (a *App) activityFromEvent(event events.Event) map[string]interface{} {
+	activity := activityFromEvent(event)
+	workspaceRoot := firstPayloadText(activity, "workspaceRootPath")
+	if workspaceRoot == "" || a == nil || a.workspace == nil {
+		activity["sessionScope"] = map[string]interface{}{"kind": "unassigned"}
+		return activity
+	}
+	identity, err := a.workspace.GetWorkspaceIdentity(workspaceRoot)
+	if err != nil {
+		activity["sessionScope"] = map[string]interface{}{"kind": "unassigned"}
+		return activity
+	}
+	activity["workspaceId"] = identity.WorkspaceID
+	activity["workspaceRootPath"] = identity.RootPath
+	activity["sessionScope"] = map[string]interface{}{"kind": "workspace", "workspaceId": identity.WorkspaceID}
+	return activity
+}
+
 func eventPayloadMap(payload interface{}) map[string]interface{} {
 	switch value := payload.(type) {
 	case map[string]interface{}:
@@ -1014,6 +1217,40 @@ func (a *App) ReadPluginDataJSON(pluginID, name string) map[string]interface{} {
 	return data
 }
 
+// ReadPluginDataNDJSON reads append-only plugin data without exposing the
+// underlying vault path to plugin frontends.
+func (a *App) ReadPluginDataNDJSON(pluginID, name string) []map[string]interface{} {
+	if _, err := a.requirePluginAccess(pluginID, "storage.namespace"); err != nil {
+		log.Printf("[api] ReadPluginDataNDJSON(%s, %s): %v", pluginID, name, err)
+		return []map[string]interface{}{}
+	}
+	if a.storage == nil {
+		return []map[string]interface{}{}
+	}
+	data, err := a.storage.ReadPluginDataNDJSON(pluginID, name)
+	if err != nil {
+		log.Printf("[api] ReadPluginDataNDJSON(%s, %s): %v", pluginID, name, err)
+		return []map[string]interface{}{}
+	}
+	return data
+}
+
+// WritePluginDataNDJSON replaces append-only data after an explicit user
+// action, such as clearing activity history.
+func (a *App) WritePluginDataNDJSON(pluginID, name string, data []map[string]interface{}) string {
+	if _, err := a.requirePluginAccess(pluginID, "storage.namespace"); err != nil {
+		return err.Error()
+	}
+	if a.storage == nil {
+		return "storage not initialized"
+	}
+	if err := a.storage.WritePluginDataNDJSON(pluginID, name, data); err != nil {
+		log.Printf("[api] WritePluginDataNDJSON(%s, %s): %v", pluginID, name, err)
+		return err.Error()
+	}
+	return ""
+}
+
 // WritePluginDataJSON writes a named JSON data file for a plugin.
 func (a *App) WritePluginDataJSON(pluginID, name string, data map[string]interface{}) string {
 	if _, err := a.requirePluginAccess(pluginID, "storage.namespace"); err != nil {
@@ -1321,6 +1558,22 @@ func (a *App) OpenVaultPathExternal(pluginID, relativePath string) string {
 	return ""
 }
 
+// OpenExternalURL opens an HTTP(S) URL through the platform browser opener.
+// This deliberately bypasses OS file associations for InternetShortcut files.
+func (a *App) OpenExternalURL(pluginID, rawURL string) string {
+	if _, err := a.requirePluginAccess(pluginID, "files.openExternal"); err != nil {
+		return err.Error()
+	}
+	parsed, err := url.ParseRequestURI(strings.TrimSpace(rawURL))
+	if err != nil || parsed.Host == "" || (parsed.Scheme != "http" && parsed.Scheme != "https") {
+		return "invalid HTTP(S) URL"
+	}
+	if err := a.externalOpenService().OpenPath(parsed.String()); err != nil {
+		return err.Error()
+	}
+	return ""
+}
+
 // ShowVaultPathInFolder reveals a vault-relative file or folder in the OS file manager.
 func (a *App) ShowVaultPathInFolder(pluginID, relativePath string) string {
 	if _, err := a.requirePluginAccess(pluginID, "files.openExternal"); err != nil {
@@ -1950,6 +2203,29 @@ func (a *App) ListWorkspaceTemplates() ([]workspace.WorkspaceTemplate, string) {
 	return a.workspace.ListWorkspaceTemplates(), ""
 }
 
+// ListWorkspaceIdentities returns durable workspace identities for relation-aware plugins.
+func (a *App) ListWorkspaceIdentities() ([]workspace.WorkspaceIdentity, string) {
+	if a.workspace == nil {
+		return nil, "workspace not initialized"
+	}
+	identities, err := a.workspace.ListWorkspaceIdentities()
+	if err != nil {
+		return nil, err.Error()
+	}
+	return identities, ""
+}
+
+// RepairWorkspaceIdentity resolves a duplicated workspace marker without moving relations.
+func (a *App) RepairWorkspaceIdentity(keepName, regenerateName string) string {
+	if a.workspace == nil {
+		return "workspace not initialized"
+	}
+	if err := a.workspace.RepairWorkspaceIdentity(keepName, regenerateName); err != nil {
+		return err.Error()
+	}
+	return ""
+}
+
 // CreateWorkspace creates a top-level physical workspace folder.
 func (a *App) CreateWorkspace(name, templateID string) (workspace.Workspace, string) {
 	if a.workspace == nil {
@@ -1961,6 +2237,7 @@ func (a *App) CreateWorkspace(name, templateID string) (workspace.Workspace, str
 	}
 	a.publishWorkspaceLifecycleEvent(workspaceCreatedEventName, map[string]interface{}{
 		"operation":         "create",
+		"workspaceId":       ws.ID,
 		"workspaceRootPath": ws.RootPath,
 		"workspaceName":     ws.Name,
 		"templateId":        templateID,
@@ -1976,8 +2253,13 @@ func (a *App) RenameWorkspace(oldName, newName string) string {
 	if err := a.workspace.RenameWorkspace(oldName, newName); err != nil {
 		return err.Error()
 	}
+	identity, err := a.workspace.GetWorkspaceIdentity(newName)
+	if err != nil {
+		return err.Error()
+	}
 	a.publishWorkspaceLifecycleEvent(workspaceRenamedEventName, map[string]interface{}{
 		"operation":                 "rename",
+		"workspaceId":               identity.WorkspaceID,
 		"workspaceRootPath":         newName,
 		"workspaceName":             newName,
 		"previousWorkspaceRootPath": oldName,
@@ -1997,6 +2279,7 @@ func (a *App) TrashWorkspace(name string) (workspace.TrashResult, string) {
 	}
 	a.publishWorkspaceLifecycleEvent(workspaceTrashedEventName, map[string]interface{}{
 		"operation":         "trash",
+		"workspaceId":       result.WorkspaceID,
 		"workspaceRootPath": name,
 		"workspaceName":     name,
 		"trashId":           result.TrashID,
@@ -2006,6 +2289,47 @@ func (a *App) TrashWorkspace(name string) (workspace.TrashResult, string) {
 	return result, ""
 }
 
+// RestoreWorkspaceTrash restores a trashed workspace and publishes its durable identity.
+func (a *App) RestoreWorkspaceTrash(trashID, targetName string) (workspace.Workspace, string) {
+	if a.workspace == nil {
+		return workspace.Workspace{}, "workspace not initialized"
+	}
+	restored, err := a.workspace.RestoreWorkspaceTrash(trashID, targetName)
+	if err != nil {
+		return workspace.Workspace{}, err.Error()
+	}
+	a.publishWorkspaceLifecycleEvent(workspaceRestoredEventName, map[string]interface{}{
+		"operation":         "restore",
+		"workspaceId":       restored.ID,
+		"workspaceRootPath": restored.RootPath,
+		"workspaceName":     restored.Name,
+		"trashId":           trashID,
+	})
+	return restored, ""
+}
+
+// PurgeWorkspaceTrash permanently removes a trashed workspace and publishes its former identity.
+func (a *App) PurgeWorkspaceTrash(trashID string) string {
+	if a.workspace == nil {
+		return "workspace not initialized"
+	}
+	identity, err := a.workspace.GetWorkspaceTrashIdentity(trashID)
+	if err != nil {
+		return err.Error()
+	}
+	if err := a.workspace.PurgeWorkspaceTrash(trashID); err != nil {
+		return err.Error()
+	}
+	a.publishWorkspaceLifecycleEvent(workspacePurgedEventName, map[string]interface{}{
+		"operation":         "purge",
+		"workspaceId":       identity.WorkspaceID,
+		"workspaceRootPath": identity.RootPath,
+		"workspaceName":     identity.RootPath,
+		"trashId":           trashID,
+	})
+	return ""
+}
+
 // GetWorkspaceMetadata returns metadata or a generic fallback for a workspace.
 func (a *App) GetWorkspaceMetadata(name string) (workspace.Metadata, string) {
 	if a.workspace == nil {
@@ -2039,7 +2363,13 @@ func (a *App) GetCurrentWorkspace() map[string]interface{} {
 	if err != nil {
 		return map[string]interface{}{"error": err.Error()}
 	}
+	identity, err := a.workspace.GetWorkspaceIdentity(node.Name)
+	if err != nil {
+		return map[string]interface{}{"error": err.Error()}
+	}
 	return map[string]interface{}{
+		"id":          identity.WorkspaceID,
+		"workspaceId": identity.WorkspaceID,
 		"name":        node.Name,
 		"rootPath":    node.RootPath,
 	}

internal/api/app_test.go

@@ -593,21 +593,14 @@ func TestActivityProviderRecordsFileChangedWithoutMountedView(t *testing.T) {
 		t.Fatalf("WriteVaultTextFile: %s", errStr)
 	}
 
-	settings, err := app.storage.ReadPluginSettings("verstak.activity")
+	stored, err := app.storage.ReadPluginDataNDJSON("verstak.activity", activityRawDataName)
 	if err != nil {
-		t.Fatalf("ReadPluginSettings: %v", err)
+		t.Fatalf("ReadPluginDataNDJSON: %v", err)
-	}
-	stored, ok := settings["events:workspace:Project"].([]interface{})
-	if !ok {
-		t.Fatalf("events:workspace:Project = %#v, want []interface{}", settings["events:workspace:Project"])
 	}
 	if len(stored) != 1 {
 		t.Fatalf("stored %d activity events, want 1", len(stored))
 	}
-	activity, ok := stored[0].(map[string]interface{})
+	activity := stored[0]
-	if !ok {
-		t.Fatalf("activity = %#v, want map[string]interface{}", stored[0])
-	}
 	if activity["type"] != "file.changed" {
 		t.Fatalf("activity type = %#v, want file.changed", activity["type"])
 	}
@@ -619,6 +612,51 @@ func TestActivityProviderRecordsFileChangedWithoutMountedView(t *testing.T) {
 	}
 }
 
+func TestBrowserActivityBatchPersistsWithoutMountedViewAndDeduplicates(t *testing.T) {
+	v := vault.NewVault(nil)
+	if err := v.CreateVault(t.TempDir()); err != nil {
+		t.Fatalf("CreateVault: %v", err)
+	}
+	app := &App{
+		storage: storage.New(v),
+		vault:   v,
+		plugins: []plugin.Plugin{{
+			Manifest: plugin.Manifest{ID: activityPluginID, Permissions: []string{"storage.namespace"}},
+			Status:   plugin.StatusLoaded,
+			Enabled:  true,
+		}},
+	}
+	event := events.Event{
+		Name:      "browser.activity.batch",
+		Timestamp: "2026-07-12T10:05:01Z",
+		Payload: map[string]interface{}{
+			"batchId": "batch-activity-1",
+			"entries": []map[string]interface{}{{
+				"hostname": "example.com", "startedAt": "2026-07-12T10:00:00Z", "endedAt": "2026-07-12T10:05:00Z", "durationSeconds": int64(300),
+			}},
+		},
+	}
+	if err := app.recordBrowserActivityBatch(event); err != nil {
+		t.Fatalf("recordBrowserActivityBatch: %v", err)
+	}
+	if err := app.recordBrowserActivityBatch(event); err != nil {
+		t.Fatalf("recordBrowserActivityBatch retry: %v", err)
+	}
+	records, err := app.storage.ReadPluginDataNDJSON(activityPluginID, activityRawDataName)
+	if err != nil {
+		t.Fatalf("ReadPluginDataNDJSON: %v", err)
+	}
+	if len(records) != 1 {
+		t.Fatalf("records = %+v, want one idempotent domain activity", records)
+	}
+	if records[0]["type"] != "browser.activity.domain" || records[0]["hostname"] != "example.com" {
+		t.Fatalf("record = %+v, want domain-only activity", records[0])
+	}
+	if _, ok := records[0]["url"]; ok {
+		t.Fatalf("record must not contain URL: %+v", records[0])
+	}
+}
+
 func TestBrowserInboxRecordsCaptureWithoutMountedView(t *testing.T) {
 	v := vault.NewVault(nil)
 	if err := v.CreateVault(t.TempDir()); err != nil {
@@ -661,6 +699,9 @@ func TestBrowserInboxRecordsCaptureWithoutMountedView(t *testing.T) {
 	bus.Publish(events.Event{Name: browserInboxMutationEvent, Payload: map[string]interface{}{
 		"pluginId": browserInboxPluginID, "action": "processed", "captureId": "capture-background", "processed": true,
 	}})
+	bus.Publish(events.Event{Name: browserInboxMutationEvent, Payload: map[string]interface{}{
+		"pluginId": browserInboxPluginID, "action": "archive", "captureId": "capture-background",
+	}})
 	if err := app.recordBrowserCapture(events.Event{
 		Name: "browser.capture.page",
 		Payload: map[string]interface{}{
@@ -683,11 +724,154 @@ func TestBrowserInboxRecordsCaptureWithoutMountedView(t *testing.T) {
 	if !ok {
 		t.Fatalf("capture = %#v, want map[string]interface{}", stored[0])
 	}
-	if capture["captureId"] != "capture-background" || capture["title"] != "Background capture" || capture["workspaceRootPath"] != "Project" || capture["processed"] != true {
+	if capture["captureId"] != "capture-background" || capture["title"] != "Background capture" || capture["workspaceRootPath"] != "Project" || capture["processed"] != true || capture["globalState"] != "archived" {
 		t.Fatalf("stored capture = %#v", capture)
 	}
 }
 
+func TestBrowserInboxArchiveKeepsAssignmentUntilExplicitPermanentDelete(t *testing.T) {
+	v := vault.NewVault(nil)
+	if err := v.CreateVault(t.TempDir()); err != nil {
+		t.Fatalf("CreateVault: %v", err)
+	}
+	bus := events.NewBus()
+	app := &App{
+		eventBus: bus,
+		storage:  storage.New(v),
+		vault:    v,
+		plugins: []plugin.Plugin{{
+			Manifest: plugin.Manifest{ID: browserInboxPluginID, Permissions: []string{"storage.namespace"}},
+			Status:   plugin.StatusLoaded,
+			Enabled:  true,
+		}},
+	}
+	app.ensureBrowserInboxSubscriptions()
+	if err := app.recordBrowserCapture(events.Event{Name: "browser.capture.page", Payload: map[string]interface{}{
+		"captureId": "archive-1", "capturedAt": "2026-07-12T10:00:00Z", "url": "https://example.com", "workspaceRootPath": "Project",
+	}}); err != nil {
+		t.Fatalf("recordBrowserCapture: %v", err)
+	}
+	bus.Publish(events.Event{Name: browserInboxMutationEvent, Payload: map[string]interface{}{
+		"pluginId": browserInboxPluginID, "action": "archive", "captureId": "archive-1",
+	}})
+	settings, err := app.storage.ReadPluginSettings(browserInboxPluginID)
+	if err != nil {
+		t.Fatalf("ReadPluginSettings: %v", err)
+	}
+	captures, _ := settings[browserInboxGlobalKey].([]interface{})
+	if len(captures) != 1 {
+		t.Fatalf("captures after archive = %#v, want retained capture", captures)
+	}
+	archived := captures[0].(map[string]interface{})
+	if archived["workspaceRootPath"] != "Project" || archived["globalState"] != "archived" {
+		t.Fatalf("archived capture = %#v, want preserved assignment", archived)
+	}
+	bus.Publish(events.Event{Name: browserInboxMutationEvent, Payload: map[string]interface{}{
+		"pluginId": browserInboxPluginID, "action": "delete", "captureId": "archive-1", "permanent": true,
+	}})
+	settings, err = app.storage.ReadPluginSettings(browserInboxPluginID)
+	if err != nil {
+		t.Fatalf("ReadPluginSettings after delete: %v", err)
+	}
+	captures, _ = settings[browserInboxGlobalKey].([]interface{})
+	if len(captures) != 0 {
+		t.Fatalf("captures after permanent delete = %#v, want none", captures)
+	}
+}
+
+func TestBrowserInboxWorkspaceReferenceSurvivesRenameAndTrash(t *testing.T) {
+	v := vault.NewVault(nil)
+	if err := v.CreateVault(t.TempDir()); err != nil {
+		t.Fatalf("CreateVault: %v", err)
+	}
+	manager := workspace.NewManager(v.GetVaultPath())
+	created, err := manager.CreateWorkspace("Project", "minimal")
+	if err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	bus := events.NewBus()
+	app := &App{
+		eventBus:  bus,
+		storage:   storage.New(v),
+		vault:     v,
+		workspace: manager,
+		plugins: []plugin.Plugin{{
+			Manifest: plugin.Manifest{ID: browserInboxPluginID, Permissions: []string{"storage.namespace"}},
+			Status:   plugin.StatusLoaded,
+			Enabled:  true,
+		}},
+	}
+	app.ensureBrowserInboxSubscriptions()
+	if err := app.recordBrowserCapture(events.Event{Name: "browser.capture.page", Payload: map[string]interface{}{
+		"captureId": "workspace-ref", "capturedAt": "2026-07-12T10:00:00Z", "url": "https://example.com", "workspaceRootPath": "Project",
+	}}); err != nil {
+		t.Fatalf("recordBrowserCapture: %v", err)
+	}
+	if errStr := app.RenameWorkspace("Project", "Client"); errStr != "" {
+		t.Fatalf("RenameWorkspace: %s", errStr)
+	}
+	if _, errStr := app.TrashWorkspace("Client"); errStr != "" {
+		t.Fatalf("TrashWorkspace: %s", errStr)
+	}
+	settings, err := app.storage.ReadPluginSettings(browserInboxPluginID)
+	if err != nil {
+		t.Fatalf("ReadPluginSettings: %v", err)
+	}
+	capture := settings[browserInboxGlobalKey].([]interface{})[0].(map[string]interface{})
+	if capture["workspaceId"] != created.ID || capture["workspaceRootPath"] != "Client" || capture["workspaceState"] != "trashed" || capture["workspaceTrashId"] == "" {
+		t.Fatalf("workspace reference = %#v", capture)
+	}
+}
+
+func TestOpenExternalURLUsesBrowserOpenService(t *testing.T) {
+	app, _ := newFilesTestApp(t, []string{"files.openExternal"})
+	opened := ""
+	app.externalOpen = newTestExternalOpenService(func(path string) error {
+		opened = path
+		return nil
+	})
+	if errStr := app.OpenExternalURL("files.plugin", "https://example.com/path"); errStr != "" {
+		t.Fatalf("OpenExternalURL: %s", errStr)
+	}
+	if opened != "https://example.com/path" {
+		t.Fatalf("opened = %q, want URL", opened)
+	}
+	if errStr := app.OpenExternalURL("files.plugin", "ftp://example.com"); errStr == "" {
+		t.Fatal("OpenExternalURL accepted unsupported URL scheme")
+	}
+}
+
+func TestJournalHandledSessionPersistsActivityWatermark(t *testing.T) {
+	v := vault.NewVault(nil)
+	if err := v.CreateVault(t.TempDir()); err != nil {
+		t.Fatalf("CreateVault: %v", err)
+	}
+	bus := events.NewBus()
+	app := &App{
+		eventBus:        bus,
+		storage:         storage.New(v),
+		vault:           v,
+		contribRegistry: contribution.NewRegistry(),
+		plugins: []plugin.Plugin{
+			{Manifest: plugin.Manifest{ID: activityPluginID, Permissions: []string{"storage.namespace"}}, Status: plugin.StatusLoaded, Enabled: true},
+			{Manifest: plugin.Manifest{ID: "verstak.journal", Permissions: []string{"events.publish"}}, Status: plugin.StatusLoaded, Enabled: true},
+		},
+	}
+	app.ensureActivityProviderSubscriptions()
+	bus.Publish(events.Event{Name: activitySessionHandledEvent, Payload: map[string]interface{}{
+		"pluginId": "verstak.journal", "sessionId": "session-1", "handledThrough": "2026-07-12T10:30:00Z", "status": "accepted",
+	}})
+	settings, err := app.storage.ReadPluginSettings(activityPluginID)
+	if err != nil {
+		t.Fatalf("ReadPluginSettings: %v", err)
+	}
+	handled := settings[activitySessionHandlingKey].(map[string]interface{})
+	record := handled["session-1"].(map[string]interface{})
+	if record["status"] != "accepted" || record["handledThrough"] != "2026-07-12T10:30:00Z" {
+		t.Fatalf("handled record = %#v", record)
+	}
+}
+
 func TestBrowserInboxRejectsCaptureWithoutOpenVault(t *testing.T) {
 	v := vault.NewVault(nil)
 	app := &App{
@@ -1826,6 +2010,10 @@ func TestWorkspaceAPIPublishesLifecycleEvents(t *testing.T) {
 	if errStr := app.SetCurrentWorkspace("Project"); errStr != "" {
 		t.Fatalf("SetCurrentWorkspace: %s", errStr)
 	}
+	currentID, ok := app.GetCurrentWorkspace()["workspaceId"].(string)
+	if !ok || currentID == "" {
+		t.Fatalf("GetCurrentWorkspace workspaceId = %#v", app.GetCurrentWorkspace()["workspaceId"])
+	}
 	if errStr := app.RenameWorkspace("Project", "Renamed"); errStr != "" {
 		t.Fatalf("RenameWorkspace: %s", errStr)
 	}
@@ -1836,6 +2024,10 @@ func TestWorkspaceAPIPublishesLifecycleEvents(t *testing.T) {
 	if got := received["workspace.created"]["workspaceRootPath"]; got != "Project" {
 		t.Fatalf("workspace.created workspaceRootPath = %#v, want Project", got)
 	}
+	createdID, _ := received["workspace.created"]["workspaceId"].(string)
+	if createdID == "" {
+		t.Fatal("workspace.created workspaceId is empty")
+	}
 	if got := received["workspace.created"]["templateId"]; got != "client-project" {
 		t.Fatalf("workspace.created templateId = %#v, want client-project", got)
 	}
@@ -1845,17 +2037,88 @@ func TestWorkspaceAPIPublishesLifecycleEvents(t *testing.T) {
 	if got := received["workspace.renamed"]["workspaceRootPath"]; got != "Renamed" {
 		t.Fatalf("workspace.renamed workspaceRootPath = %#v, want Renamed", got)
 	}
+	if got := received["workspace.renamed"]["workspaceId"]; got != createdID {
+		t.Fatalf("workspace.renamed workspaceId = %#v, want %q", got, createdID)
+	}
 	if got := received["workspace.renamed"]["previousWorkspaceRootPath"]; got != "Project" {
 		t.Fatalf("workspace.renamed previousWorkspaceRootPath = %#v, want Project", got)
 	}
 	if got := received["workspace.trashed"]["workspaceRootPath"]; got != "Renamed" {
 		t.Fatalf("workspace.trashed workspaceRootPath = %#v, want Renamed", got)
 	}
+	if got := received["workspace.trashed"]["workspaceId"]; got != createdID {
+		t.Fatalf("workspace.trashed workspaceId = %#v, want %q", got, createdID)
+	}
 	if got := received["workspace.trashed"]["trashPath"]; got == "" {
 		t.Fatalf("workspace.trashed trashPath = %#v, want non-empty", got)
 	}
 }
 
+func TestWorkspaceIdentityAPIListsAndRepairsDuplicates(t *testing.T) {
+	app, vaultDir := newFilesTestApp(t, []string{"files.read"})
+	app.workspace = workspace.NewManager(vaultDir)
+	if err := app.workspace.Load(); err != nil {
+		t.Fatal(err)
+	}
+	if _, errStr := app.CreateWorkspace("Original", "default"); errStr != "" {
+		t.Fatalf("CreateWorkspace: %s", errStr)
+	}
+	identities, errStr := app.ListWorkspaceIdentities()
+	if errStr != "" {
+		t.Fatalf("ListWorkspaceIdentities: %s", errStr)
+	}
+	var original workspace.WorkspaceIdentity
+	for _, identity := range identities {
+		if identity.RootPath == "Original" {
+			original = identity
+			break
+		}
+	}
+	if original.WorkspaceID == "" || original.State != "active" {
+		t.Fatalf("identities = %+v", identities)
+	}
+}
+
+func TestWorkspaceTrashRestoreAndPurgePublishIdentityLifecycle(t *testing.T) {
+	app, vaultDir := newFilesTestApp(t, []string{"files.read"})
+	app.workspace = workspace.NewManager(vaultDir)
+	app.eventBus = events.NewBus()
+	if err := app.workspace.Load(); err != nil {
+		t.Fatal(err)
+	}
+	received := map[string]map[string]interface{}{}
+	for _, eventName := range []string{"workspace.restored", "workspace.purged"} {
+		name := eventName
+		app.eventBus.Subscribe(name, func(event events.Event) {
+			received[name], _ = event.Payload.(map[string]interface{})
+		})
+	}
+	if _, errStr := app.CreateWorkspace("Client", "default"); errStr != "" {
+		t.Fatalf("CreateWorkspace: %s", errStr)
+	}
+	trashed, errStr := app.TrashWorkspace("Client")
+	if errStr != "" {
+		t.Fatalf("TrashWorkspace: %s", errStr)
+	}
+	restored, errStr := app.RestoreWorkspaceTrash(trashed.TrashID, "Client-Restored")
+	if errStr != "" {
+		t.Fatalf("RestoreWorkspaceTrash: %s", errStr)
+	}
+	if got := received["workspace.restored"]["workspaceId"]; got != restored.ID {
+		t.Fatalf("restored workspaceId = %#v, want %q", got, restored.ID)
+	}
+	trashed, errStr = app.TrashWorkspace("Client-Restored")
+	if errStr != "" {
+		t.Fatalf("TrashWorkspace restored: %s", errStr)
+	}
+	if errStr := app.PurgeWorkspaceTrash(trashed.TrashID); errStr != "" {
+		t.Fatalf("PurgeWorkspaceTrash: %s", errStr)
+	}
+	if got := received["workspace.purged"]["workspaceId"]; got != restored.ID {
+		t.Fatalf("purged workspaceId = %#v, want %q", got, restored.ID)
+	}
+}
+
 func TestMoveWorkspaceNodeCompatibilityIsUnsupported(t *testing.T) {
 	app, vaultDir := newFilesTestApp(t, []string{"files.read"})
 	app.workspace = workspace.NewManager(vaultDir)

internal/core/browserreceiver/receiver.go

@@ -12,18 +12,20 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"net/url"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/verstak/verstak-desktop/internal/core/events"
+	"github.com/verstak/verstak-desktop/internal/core/hostname"
 )
 
 const (
 	capturePath         = "/api/browser-inbox/v1/captures"
+	activityBatchPath   = "/api/browser-activity/v1/batches"
 	DefaultAddr         = "127.0.0.1:47731"
 	DefaultCaptureURL   = "http://" + DefaultAddr + capturePath
+	DefaultActivityURL  = "http://" + DefaultAddr + activityBatchPath
 	receiverTokenHeader = "X-Verstak-Receiver-Token"
 )
 
@@ -43,6 +45,9 @@ const (
 	maxFileTextBytes       = 2 * 1024 * 1024
 	maxFileBytes           = 8 * 1024 * 1024
 	maxFileDataBase64Bytes = 4 * ((maxFileBytes + 2) / 3)
+	maxActivityBodyBytes   = 256 * 1024
+	maxActivityEntries     = 100
+	maxActivityDuration    = 10 * time.Minute
 )
 
 type Receiver struct {
@@ -59,6 +64,8 @@ type Options struct {
 	ReceiverToken     string
 	Available         func() bool
 	Persist           func(events.Event) error
+	ActivityAvailable func() bool
+	PersistActivity   func(events.Event) error
 }
 
 type Server struct {
@@ -107,6 +114,23 @@ type CaptureBrowser struct {
 	Name string `json:"name"`
 }
 
+// ActivityBatchPayload contains only domain-level time accounting. It never
+// accepts or emits page URLs, titles, content, or navigation history.
+type ActivityBatchPayload struct {
+	SchemaVersion int             `json:"schemaVersion"`
+	BatchID       string          `json:"batchId"`
+	CreatedAt     string          `json:"createdAt"`
+	Source        string          `json:"source"`
+	Entries       []ActivityEntry `json:"entries"`
+}
+
+type ActivityEntry struct {
+	Hostname        string `json:"hostname"`
+	StartedAt       string `json:"startedAt"`
+	EndedAt         string `json:"endedAt"`
+	DurationSeconds int64  `json:"durationSeconds"`
+}
+
 func New(bus *events.Bus, providers ...WorkspaceProvider) *Receiver {
 	return NewWithOptions(bus, Options{}, providers...)
 }
@@ -141,6 +165,18 @@ func (r *Receiver) SetPersistence(available func() bool, persist func(events.Eve
 	r.options.Persist = persist
 }
 
+// SetActivityPersistence configures durable passive browser activity storage.
+// An acknowledgement is sent only after persist returns successfully.
+func (r *Receiver) SetActivityPersistence(available func() bool, persist func(events.Event) error) {
+	if r == nil {
+		return
+	}
+	r.optionsMu.Lock()
+	defer r.optionsMu.Unlock()
+	r.options.ActivityAvailable = available
+	r.options.PersistActivity = persist
+}
+
 func Start(addr string, receiver *Receiver) (*Server, error) {
 	if receiver == nil {
 		return nil, fmt.Errorf("receiver is required")
@@ -181,6 +217,10 @@ func (s *Server) Close() error {
 func (r *Receiver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 
+	if req.URL.Path == activityBatchPath {
+		r.serveActivityBatch(w, req)
+		return
+	}
 	if req.URL.Path != capturePath {
 		http.NotFound(w, req)
 		return
@@ -256,6 +296,59 @@ func (r *Receiver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	})
 }
 
+func (r *Receiver) serveActivityBatch(w http.ResponseWriter, req *http.Request) {
+	if req.Method != http.MethodPost {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		_ = json.NewEncoder(w).Encode(map[string]string{"error": "method not allowed"})
+		return
+	}
+	if err := r.validateReceiverToken(req); err != nil {
+		writeError(w, http.StatusUnauthorized, err.Error())
+		return
+	}
+	options := r.currentOptions()
+	if options.ActivityAvailable == nil || !options.ActivityAvailable() || options.PersistActivity == nil {
+		writeError(w, http.StatusServiceUnavailable, "activity storage unavailable")
+		return
+	}
+
+	defer req.Body.Close()
+	decoder := json.NewDecoder(http.MaxBytesReader(w, req.Body, maxActivityBodyBytes))
+	var batch ActivityBatchPayload
+	if err := decoder.Decode(&batch); err != nil {
+		writeActivityDecodeError(w, err)
+		return
+	}
+	if err := decoder.Decode(&struct{}{}); err != io.EOF {
+		writeActivityDecodeError(w, err)
+		return
+	}
+	if err := batch.NormalizeAndValidate(); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	event := events.Event{
+		Name:      "browser.activity.batch",
+		Timestamp: time.Now().UTC().Format(time.RFC3339Nano),
+		Payload:   batch.EventPayload(),
+	}
+	if err := options.PersistActivity(event); err != nil {
+		log.Printf("[browserreceiver] persist activity %s: %v", batch.BatchID, err)
+		writeError(w, http.StatusServiceUnavailable, "activity storage unavailable")
+		return
+	}
+	if r.bus != nil {
+		r.bus.Publish(event)
+	}
+
+	w.WriteHeader(http.StatusAccepted)
+	_ = json.NewEncoder(w).Encode(map[string]string{
+		"status":  "accepted",
+		"batchId": batch.BatchID,
+	})
+}
+
 func (r *Receiver) currentOptions() Options {
 	if r == nil {
 		return Options{}
@@ -370,6 +463,80 @@ func (p CapturePayload) Validate() error {
 	return nil
 }
 
+// NormalizeAndValidate validates a batch before it is made durable and replaces
+// each submitted hostname with the shared canonical A-label form.
+func (p *ActivityBatchPayload) NormalizeAndValidate() error {
+	if p == nil || p.SchemaVersion != 1 {
+		return fmt.Errorf("unsupported schemaVersion")
+	}
+	if strings.TrimSpace(p.BatchID) == "" {
+		return fmt.Errorf("batchId is required")
+	}
+	if err := validateCaptureText(p.BatchID, "batchId", maxCaptureIDBytes); err != nil {
+		return err
+	}
+	if strings.TrimSpace(p.CreatedAt) == "" {
+		return fmt.Errorf("createdAt is required")
+	}
+	if _, err := time.Parse(time.RFC3339, p.CreatedAt); err != nil {
+		return fmt.Errorf("createdAt is invalid")
+	}
+	if err := validateCaptureText(p.CreatedAt, "createdAt", maxCapturedAtBytes); err != nil {
+		return err
+	}
+	if strings.TrimSpace(p.Source) == "" {
+		return fmt.Errorf("source is required")
+	}
+	if err := validateCaptureText(p.Source, "source", maxCaptureSourceBytes); err != nil {
+		return err
+	}
+	if len(p.Entries) == 0 || len(p.Entries) > maxActivityEntries {
+		return fmt.Errorf("entries must contain between 1 and %d items", maxActivityEntries)
+	}
+	for index := range p.Entries {
+		entry := &p.Entries[index]
+		canonical := hostname.NormalizeHostnameV1(entry.Hostname)
+		if canonical == "" {
+			return fmt.Errorf("entries[%d].hostname is invalid", index)
+		}
+		startedAt, err := time.Parse(time.RFC3339, entry.StartedAt)
+		if err != nil {
+			return fmt.Errorf("entries[%d].startedAt is invalid", index)
+		}
+		endedAt, err := time.Parse(time.RFC3339, entry.EndedAt)
+		if err != nil {
+			return fmt.Errorf("entries[%d].endedAt is invalid", index)
+		}
+		interval := endedAt.Sub(startedAt)
+		if interval <= 0 || interval > maxActivityDuration {
+			return fmt.Errorf("entries[%d] interval must be between 1 second and %s", index, maxActivityDuration)
+		}
+		if entry.DurationSeconds <= 0 || entry.DurationSeconds > int64(maxActivityDuration/time.Second) || time.Duration(entry.DurationSeconds)*time.Second > interval {
+			return fmt.Errorf("entries[%d].durationSeconds is invalid", index)
+		}
+		entry.Hostname = canonical
+	}
+	return nil
+}
+
+func (p ActivityBatchPayload) EventPayload() map[string]interface{} {
+	entries := make([]map[string]interface{}, 0, len(p.Entries))
+	for _, entry := range p.Entries {
+		entries = append(entries, map[string]interface{}{
+			"hostname":        entry.Hostname,
+			"startedAt":       entry.StartedAt,
+			"endedAt":         entry.EndedAt,
+			"durationSeconds": entry.DurationSeconds,
+		})
+	}
+	return map[string]interface{}{
+		"batchId":   strings.TrimSpace(p.BatchID),
+		"createdAt": strings.TrimSpace(p.CreatedAt),
+		"source":    strings.TrimSpace(p.Source),
+		"entries":   entries,
+	}
+}
+
 func (p CapturePayload) validateFile() error {
 	if p.File == nil || strings.TrimSpace(p.File.Name) == "" {
 		return fmt.Errorf("file.name is required")
@@ -450,10 +617,19 @@ func (p CapturePayload) EventPayload() map[string]interface{} {
 }
 
 func captureDomain(rawURL, fallback string) string {
-	if u, err := url.Parse(strings.TrimSpace(rawURL)); err == nil && u.Hostname() != "" {
+	if normalized := hostname.NormalizeURLHostnameV1(rawURL); normalized != "" {
-		return u.Hostname()
+		return normalized
 	}
-	return strings.TrimSpace(fallback)
+	return hostname.NormalizeHostnameV1(fallback)
+}
+
+func writeActivityDecodeError(w http.ResponseWriter, err error) {
+	var maxBytesErr *http.MaxBytesError
+	if errors.As(err, &maxBytesErr) {
+		writeError(w, http.StatusRequestEntityTooLarge, "activity payload exceeds limit")
+		return
+	}
+	writeError(w, http.StatusBadRequest, "invalid JSON")
 }
 
 func writeError(w http.ResponseWriter, status int, message string) {

internal/core/browserreceiver/receiver_test.go

@@ -238,6 +238,101 @@ func TestReceiverLeavesCaptureUnassignedWithoutCurrentWorkspace(t *testing.T) {
 	}
 }
 
+func TestReceiverAcceptsDomainActivityBatchAfterDurablePersistence(t *testing.T) {
+	bus := events.NewBus()
+	received := make(chan events.Event, 1)
+	bus.Subscribe("browser.activity.batch", func(event events.Event) {
+		received <- event
+	})
+	persisted := 0
+	receiver := NewWithOptions(bus, Options{
+		ActivityAvailable: func() bool { return true },
+		PersistActivity: func(event events.Event) error {
+			persisted++
+			return nil
+		},
+	})
+	body := `{
+		"schemaVersion": 1,
+		"batchId": "batch-123",
+		"createdAt": "2026-07-12T10:05:00.000Z",
+		"source": "verstak-browser-extension",
+		"entries": [{
+			"hostname": "пример.рф",
+			"startedAt": "2026-07-12T10:00:00.000Z",
+			"endedAt": "2026-07-12T10:05:00.000Z",
+			"durationSeconds": 300
+		}]
+	}`
+	req := httptest.NewRequest(http.MethodPost, "/api/browser-activity/v1/batches", bytes.NewBufferString(body))
+	rec := httptest.NewRecorder()
+
+	receiver.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusAccepted {
+		t.Fatalf("status = %d, want %d; body=%s", rec.Code, http.StatusAccepted, rec.Body.String())
+	}
+	if persisted != 1 {
+		t.Fatalf("persisted = %d, want 1 before acknowledgement", persisted)
+	}
+	var response map[string]string
+	if err := json.Unmarshal(rec.Body.Bytes(), &response); err != nil {
+		t.Fatalf("response json: %v", err)
+	}
+	if response["batchId"] != "batch-123" || response["status"] != "accepted" {
+		t.Fatalf("response = %+v, want accepted batch-123", response)
+	}
+	event := <-received
+	payload, ok := event.Payload.(map[string]interface{})
+	if !ok {
+		t.Fatalf("event payload type = %T, want map[string]interface{}", event.Payload)
+	}
+	if payload["batchId"] != "batch-123" {
+		t.Fatalf("event payload = %+v, want batch id", payload)
+	}
+	entries, ok := payload["entries"].([]map[string]interface{})
+	if !ok || len(entries) != 1 || entries[0]["hostname"] != "xn--e1afmkfd.xn--p1ai" {
+		t.Fatalf("event entries = %+v, want one canonical hostname", payload["entries"])
+	}
+	if _, ok := payload["url"]; ok {
+		t.Fatalf("activity payload must not contain URL: %+v", payload)
+	}
+}
+
+func TestReceiverRejectsDomainActivityWithoutConsumerOrValidInterval(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		receiver *Receiver
+		body     string
+		wantCode int
+	}{
+		{
+			name:     "consumer unavailable",
+			receiver: New(events.NewBus()),
+			body:     `{"schemaVersion":1,"batchId":"batch-a","createdAt":"2026-07-12T10:05:00Z","source":"verstak-browser-extension","entries":[{"hostname":"example.com","startedAt":"2026-07-12T10:00:00Z","endedAt":"2026-07-12T10:05:00Z","durationSeconds":300}]}`,
+			wantCode: http.StatusServiceUnavailable,
+		},
+		{
+			name: "duration too long",
+			receiver: NewWithOptions(events.NewBus(), Options{
+				ActivityAvailable: func() bool { return true },
+				PersistActivity:   func(events.Event) error { return nil },
+			}),
+			body:     `{"schemaVersion":1,"batchId":"batch-b","createdAt":"2026-07-12T10:05:00Z","source":"verstak-browser-extension","entries":[{"hostname":"example.com","startedAt":"2026-07-12T10:00:00Z","endedAt":"2026-07-12T10:20:01Z","durationSeconds":1201}]}`,
+			wantCode: http.StatusBadRequest,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodPost, "/api/browser-activity/v1/batches", strings.NewReader(tc.body))
+			rec := httptest.NewRecorder()
+			tc.receiver.ServeHTTP(rec, req)
+			if rec.Code != tc.wantCode {
+				t.Fatalf("status = %d, want %d; body=%s", rec.Code, tc.wantCode, rec.Body.String())
+			}
+		})
+	}
+}
+
 func TestReceiverRequiresTokenWhenPaired(t *testing.T) {
 	bus := events.NewBus()
 	received := make(chan events.Event, 1)

internal/core/hostname/hostname.go

@@ -0,0 +1,123 @@
+package hostname
+
+import (
+	"net/netip"
+	"net/url"
+	"strings"
+	"unicode"
+
+	"golang.org/x/net/idna"
+)
+
+const (
+	maxDNSHostnameLength = 253
+	maxDNSLabelLength    = 63
+)
+
+// NormalizeHostnameV1 returns the canonical A-label hostname used by domain
+// bindings. It accepts a bare DNS name, IPv4 address, bracketed IPv6 literal,
+// localhost, or a single-label internal hostname. Invalid input returns "".
+func NormalizeHostnameV1(input string) string {
+	value := strings.TrimSpace(input)
+	if value == "" || strings.IndexFunc(value, unicode.IsSpace) >= 0 || strings.ContainsAny(value, "\\/?#@") {
+		return ""
+	}
+
+	if strings.HasPrefix(value, "[") || strings.HasSuffix(value, "]") {
+		if !strings.HasPrefix(value, "[") || !strings.HasSuffix(value, "]") {
+			return ""
+		}
+		return normalizeIPv6(value[1 : len(value)-1])
+	}
+	if strings.Contains(value, ":") {
+		return ""
+	}
+
+	value = strings.TrimSuffix(value, ".")
+	if value == "" || strings.HasSuffix(value, ".") {
+		return ""
+	}
+	if isNumericHostname(value) {
+		return normalizeIPv4(value)
+	}
+	return normalizeDNS(value)
+}
+
+// NormalizeURLHostnameV1 returns the canonical hostname from an HTTP(S) URL.
+// Ports, paths, credentials, and fragments are intentionally not preserved.
+func NormalizeURLHostnameV1(input string) string {
+	value := strings.TrimSpace(input)
+	if value == "" {
+		return ""
+	}
+	parsed, err := url.ParseRequestURI(value)
+	if err != nil || (parsed.Scheme != "http" && parsed.Scheme != "https") {
+		return ""
+	}
+	host := parsed.Hostname()
+	if host == "" {
+		return ""
+	}
+	if address, err := netip.ParseAddr(host); err == nil && address.Is6() {
+		return address.String()
+	}
+	return NormalizeHostnameV1(host)
+}
+
+func normalizeIPv4(value string) string {
+	address, err := netip.ParseAddr(value)
+	if err != nil || !address.Is4() || address.String() != value {
+		return ""
+	}
+	return address.String()
+}
+
+func normalizeIPv6(value string) string {
+	address, err := netip.ParseAddr(value)
+	if err != nil || !address.Is6() {
+		return ""
+	}
+	return address.String()
+}
+
+func normalizeDNS(value string) string {
+	ascii, err := idna.Lookup.ToASCII(value)
+	if err != nil {
+		return ""
+	}
+	ascii = strings.ToLower(strings.TrimSuffix(ascii, "."))
+	if ascii == "" || strings.HasSuffix(ascii, ".") || len(ascii) > maxDNSHostnameLength {
+		return ""
+	}
+	for _, label := range strings.Split(ascii, ".") {
+		if len(label) == 0 || len(label) > maxDNSLabelLength || !isDNSLabel(label) {
+			return ""
+		}
+	}
+	return ascii
+}
+
+func isNumericHostname(value string) bool {
+	for _, char := range value {
+		if (char < '0' || char > '9') && char != '.' {
+			return false
+		}
+	}
+	return true
+}
+
+func isDNSLabel(label string) bool {
+	if !isASCIIAlphaNum(label[0]) || !isASCIIAlphaNum(label[len(label)-1]) {
+		return false
+	}
+	for _, char := range label {
+		if !isASCIIAlphaNum(byte(char)) && char != '-' {
+			return false
+		}
+	}
+	return true
+}
+
+func isASCIIAlphaNum(char byte) bool {
+	return char >= 'a' && char <= 'z' || char >= '0' && char <= '9'
+}

internal/core/hostname/hostname_test.go

@@ -0,0 +1,50 @@
+package hostname
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+type normalizationVector struct {
+	Input  string `json:"input"`
+	Output string `json:"output"`
+}
+
+type normalizationVectors struct {
+	Bare []normalizationVector `json:"bare"`
+	URL  []normalizationVector `json:"url"`
+}
+
+func TestNormalizeHostnameV1Vectors(t *testing.T) {
+	vectors := loadVectors(t)
+	for _, vector := range vectors.Bare {
+		if got := NormalizeHostnameV1(vector.Input); got != vector.Output {
+			t.Errorf("NormalizeHostnameV1(%q) = %q, want %q", vector.Input, got, vector.Output)
+		}
+	}
+}
+
+func TestNormalizeURLHostnameV1Vectors(t *testing.T) {
+	vectors := loadVectors(t)
+	for _, vector := range vectors.URL {
+		if got := NormalizeURLHostnameV1(vector.Input); got != vector.Output {
+			t.Errorf("NormalizeURLHostnameV1(%q) = %q, want %q", vector.Input, got, vector.Output)
+		}
+	}
+}
+
+func loadVectors(t *testing.T) normalizationVectors {
+	t.Helper()
+	path := filepath.Join("testdata", "hostname-normalization-v1.json")
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read %s: %v", path, err)
+	}
+	var vectors normalizationVectors
+	if err := json.Unmarshal(data, &vectors); err != nil {
+		t.Fatalf("decode %s: %v", path, err)
+	}
+	return vectors
+}

internal/core/hostname/testdata/hostname-normalization-v1.json

@@ -0,0 +1,34 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.mirv.top/verstak/verstak-sdk/schemas/hostname-normalization-v1.json",
+  "title": "Verstak canonical hostname normalization v1 test vectors",
+  "description": "Canonical hostnames are lowercase ASCII A-labels without a port or trailing DNS dot. Bare hostnames accept DNS names, IPv4, bracketed IPv6, localhost, and internal single-label names. URL inputs accept only HTTP(S). Invalid or excessively long input normalizes to an empty string.",
+  "version": 1,
+  "bare": [
+    { "input": "example.com", "output": "example.com" },
+    { "input": " Example.COM. ", "output": "example.com" },
+    { "input": "пример.рф", "output": "xn--e1afmkfd.xn--p1ai" },
+    { "input": "bücher.example", "output": "xn--bcher-kva.example" },
+    { "input": "127.0.0.1", "output": "127.0.0.1" },
+    { "input": "[2001:db8::1]", "output": "2001:db8::1" },
+    { "input": "localhost", "output": "localhost" },
+    { "input": "intranet", "output": "intranet" },
+    { "input": "", "output": "" },
+    { "input": "https://example.com", "output": "" },
+    { "input": "example.com:443", "output": "" },
+    { "input": "user@example.com", "output": "" },
+    { "input": "bad host", "output": "" },
+    { "input": "example..com", "output": "" },
+    { "input": "example.com..", "output": "" },
+    { "input": "127.000.000.001", "output": "" },
+    { "input": "[2001:db8::1]:443", "output": "" },
+    { "input": "a...............................................................example", "output": "" }
+  ],
+  "url": [
+    { "input": "https://пример.рф/path", "output": "xn--e1afmkfd.xn--p1ai" },
+    { "input": "http://Example.COM.:8080/path", "output": "example.com" },
+    { "input": "https://[2001:db8::1]/", "output": "2001:db8::1" },
+    { "input": "ftp://example.com/path", "output": "" },
+    { "input": "not a URL", "output": "" }
+  ]
+}

internal/core/storage/api.go

@@ -20,6 +20,17 @@ type Storage struct {
 	vault *vault.Vault
 }
 
+// NDJSONRetention bounds append-only plugin data. Records are compacted after
+// a successful append so settings.json never becomes an event log.
+type NDJSONRetention struct {
+	TimestampField   string
+	MaxAge           time.Duration
+	MaxEntries       int
+	MaxBytes         int64
+	DeduplicateField string
+	DeduplicateValue string
+}
+
 // New creates a new Storage instance backed by the given vault.
 func New(v *vault.Vault) *Storage {
 	return &Storage{vault: v}
@@ -234,6 +245,204 @@ func (s *Storage) WritePluginDataJSON(pluginID, name string, data map[string]int
 	return atomicWrite(path, encoded)
 }
 
+// ReadPluginDataNDJSON reads an append-only named data file. A missing file is
+// represented by an empty slice.
+func (s *Storage) ReadPluginDataNDJSON(pluginID, name string) ([]map[string]interface{}, error) {
+	if err := validatePluginID(pluginID); err != nil {
+		return nil, err
+	}
+	if err := validateStorageName("data", name); err != nil {
+		return nil, err
+	}
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	var records []map[string]interface{}
+	err := s.withOpenVault(func(vaultPath string) error {
+		var err error
+		records, err = readPluginDataNDJSONAt(vaultPath, pluginID, name)
+		return err
+	})
+	return records, err
+}
+
+// AppendPluginDataNDJSON appends records durably and then applies bounded
+// retention. It returns false without writing when the supplied idempotency
+// value is already present in the retained log.
+func (s *Storage) AppendPluginDataNDJSON(pluginID, name string, records []map[string]interface{}, retention NDJSONRetention) (bool, error) {
+	if err := validatePluginID(pluginID); err != nil {
+		return false, err
+	}
+	if err := validateStorageName("data", name); err != nil {
+		return false, err
+	}
+	if len(records) == 0 {
+		return false, fmt.Errorf("NDJSON records are empty")
+	}
+	if retention.MaxEntries < 0 || retention.MaxBytes < 0 || retention.MaxAge < 0 {
+		return false, fmt.Errorf("NDJSON retention values must not be negative")
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	stored := false
+	err := s.withOpenVault(func(vaultPath string) error {
+		existing, err := readPluginDataNDJSONAt(vaultPath, pluginID, name)
+		if err != nil {
+			return err
+		}
+		if retention.DeduplicateField != "" && retention.DeduplicateValue != "" {
+			for _, record := range existing {
+				if fmt.Sprint(record[retention.DeduplicateField]) == retention.DeduplicateValue {
+					return nil
+				}
+			}
+		}
+		path := pluginDataNDJSONPath(vaultPath, pluginID, name)
+		if err := appendNDJSON(path, records); err != nil {
+			return err
+		}
+		stored = true
+		compacted := compactNDJSONRecords(append(existing, records...), retention, time.Now().UTC())
+		if !sameNDJSONRecords(append(existing, records...), compacted) {
+			return writeNDJSON(path, compacted)
+		}
+		return nil
+	})
+	return stored, err
+}
+
+// WritePluginDataNDJSON replaces a named append-only data file. It is reserved
+// for explicit user actions such as clearing Activity, never normal event
+// ingestion.
+func (s *Storage) WritePluginDataNDJSON(pluginID, name string, records []map[string]interface{}) error {
+	if err := validatePluginID(pluginID); err != nil {
+		return err
+	}
+	if err := validateStorageName("data", name); err != nil {
+		return err
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.withOpenVault(func(vaultPath string) error {
+		return writeNDJSON(pluginDataNDJSONPath(vaultPath, pluginID, name), records)
+	})
+}
+
+func pluginDataNDJSONPath(vaultPath, pluginID, name string) string {
+	return filepath.Join(vaultPath, ".verstak", "plugin-data", pluginID, name+".ndjson")
+}
+
+func readPluginDataNDJSONAt(vaultPath, pluginID, name string) ([]map[string]interface{}, error) {
+	data, err := os.ReadFile(pluginDataNDJSONPath(vaultPath, pluginID, name))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return []map[string]interface{}{}, nil
+		}
+		return nil, fmt.Errorf("failed to read NDJSON data %s for plugin %s: %w", name, pluginID, err)
+	}
+	if len(data) == 0 {
+		return []map[string]interface{}{}, nil
+	}
+	lines := strings.Split(strings.TrimSuffix(string(data), "\n"), "\n")
+	records := make([]map[string]interface{}, 0, len(lines))
+	for index, line := range lines {
+		if strings.TrimSpace(line) == "" {
+			continue
+		}
+		var record map[string]interface{}
+		if err := json.Unmarshal([]byte(line), &record); err != nil {
+			return nil, fmt.Errorf("corrupt NDJSON data %s line %d for plugin %s: %w", name, index+1, pluginID, err)
+		}
+		records = append(records, record)
+	}
+	return records, nil
+}
+
+func appendNDJSON(path string, records []map[string]interface{}) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return fmt.Errorf("failed to create NDJSON data directory: %w", err)
+	}
+	file, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	if err != nil {
+		return fmt.Errorf("failed to open NDJSON data file: %w", err)
+	}
+	defer file.Close()
+	for _, record := range records {
+		encoded, err := json.Marshal(record)
+		if err != nil {
+			return fmt.Errorf("failed to marshal NDJSON record: %w", err)
+		}
+		if _, err := file.Write(append(encoded, '\n')); err != nil {
+			return fmt.Errorf("failed to append NDJSON record: %w", err)
+		}
+	}
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync NDJSON data: %w", err)
+	}
+	return nil
+}
+
+func writeNDJSON(path string, records []map[string]interface{}) error {
+	data := make([]byte, 0)
+	for _, record := range records {
+		encoded, err := json.Marshal(record)
+		if err != nil {
+			return fmt.Errorf("failed to marshal NDJSON record: %w", err)
+		}
+		data = append(data, encoded...)
+		data = append(data, '\n')
+	}
+	return atomicWrite(path, data)
+}
+
+func compactNDJSONRecords(records []map[string]interface{}, retention NDJSONRetention, now time.Time) []map[string]interface{} {
+	kept := make([]map[string]interface{}, 0, len(records))
+	cutoff := now.Add(-retention.MaxAge)
+	for _, record := range records {
+		if retention.MaxAge > 0 && retention.TimestampField != "" {
+			if raw, ok := record[retention.TimestampField].(string); ok {
+				if timestamp, err := time.Parse(time.RFC3339, raw); err == nil && timestamp.Before(cutoff) {
+					continue
+				}
+			}
+		}
+		kept = append(kept, record)
+	}
+	if retention.MaxEntries > 0 && len(kept) > retention.MaxEntries {
+		kept = kept[len(kept)-retention.MaxEntries:]
+	}
+	if retention.MaxBytes > 0 {
+		for len(kept) > 0 && ndjsonSize(kept) > retention.MaxBytes {
+			kept = kept[1:]
+		}
+	}
+	return kept
+}
+
+func ndjsonSize(records []map[string]interface{}) int64 {
+	var total int64
+	for _, record := range records {
+		encoded, err := json.Marshal(record)
+		if err == nil {
+			total += int64(len(encoded) + 1)
+		}
+	}
+	return total
+}
+
+func sameNDJSONRecords(left, right []map[string]interface{}) bool {
+	if len(left) != len(right) {
+		return false
+	}
+	for index := range left {
+		leftJSON, leftErr := json.Marshal(left[index])
+		rightJSON, rightErr := json.Marshal(right[index])
+		if leftErr != nil || rightErr != nil || string(leftJSON) != string(rightJSON) {
+			return false
+		}
+	}
+	return true
+}
+
 // ─── Cache JSON API ───────────────────────────────────────
 
 // ReadPluginCacheJSON reads a named JSON cache file for a plugin.

internal/core/storage/ndjson_test.go

@@ -0,0 +1,91 @@
+package storage
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestAppendPluginDataNDJSONCompactsAndDeduplicates(t *testing.T) {
+	s, vaultDir := newTestStorage(t)
+	retention := NDJSONRetention{
+		TimestampField:   "occurredAt",
+		MaxAge:           60 * 24 * time.Hour,
+		MaxEntries:       2,
+		MaxBytes:         16 * 1024,
+		DeduplicateField: "sourceBatchId",
+		DeduplicateValue: "batch-1",
+	}
+	old := time.Now().UTC().Add(-61 * 24 * time.Hour).Format(time.RFC3339)
+	now := time.Now().UTC().Format(time.RFC3339)
+
+	stored, err := s.AppendPluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+		{"activityId": "old", "sourceBatchId": "old-batch", "occurredAt": old},
+	}, retention)
+	if err != nil || !stored {
+		t.Fatalf("old append = (%v, %v), want (true, nil)", stored, err)
+	}
+
+	stored, err = s.AppendPluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+		{"activityId": "current-1", "sourceBatchId": "batch-1", "occurredAt": now},
+	}, retention)
+	if err != nil || !stored {
+		t.Fatalf("first current append = (%v, %v), want (true, nil)", stored, err)
+	}
+
+	stored, err = s.AppendPluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+		{"activityId": "duplicate", "sourceBatchId": "batch-1", "occurredAt": now},
+	}, retention)
+	if err != nil || stored {
+		t.Fatalf("duplicate append = (%v, %v), want (false, nil)", stored, err)
+	}
+
+	for _, item := range []struct {
+		id    string
+		batch string
+	}{
+		{id: "current-2", batch: "batch-3"},
+		{id: "current-3", batch: "batch-4"},
+	} {
+		retention.DeduplicateValue = item.batch
+		if stored, err := s.AppendPluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+			{"activityId": item.id, "sourceBatchId": item.batch, "occurredAt": now},
+		}, retention); err != nil || !stored {
+			t.Fatalf("append %s = (%v, %v), want (true, nil)", item.id, stored, err)
+		}
+	}
+
+	records, err := s.ReadPluginDataNDJSON("verstak.activity", "activity-events")
+	if err != nil {
+		t.Fatalf("ReadPluginDataNDJSON: %v", err)
+	}
+	if len(records) != 2 || records[0]["activityId"] != "current-2" || records[1]["activityId"] != "current-3" {
+		t.Fatalf("records = %+v, want current-2 and current-3", records)
+	}
+	if _, err := os.Stat(filepath.Join(vaultDir, "VerstakVault", ".verstak", "plugin-data", "verstak.activity", "activity-events.ndjson")); err != nil {
+		t.Fatalf("activity data file missing: %v", err)
+	}
+}
+
+func TestWritePluginDataNDJSONReplacesRecordsForExplicitUserClear(t *testing.T) {
+	s, _ := newTestStorage(t)
+	if _, err := s.AppendPluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+		{"activityId": "one", "occurredAt": time.Now().UTC().Format(time.RFC3339)},
+		{"activityId": "two", "occurredAt": time.Now().UTC().Format(time.RFC3339)},
+	}, NDJSONRetention{}); err != nil {
+		t.Fatalf("AppendPluginDataNDJSON: %v", err)
+	}
+	if err := s.WritePluginDataNDJSON("verstak.activity", "activity-events", []map[string]interface{}{
+		{"activityId": "two", "occurredAt": time.Now().UTC().Format(time.RFC3339)},
+	}); err != nil {
+		t.Fatalf("WritePluginDataNDJSON: %v", err)
+	}
+	records, err := s.ReadPluginDataNDJSON("verstak.activity", "activity-events")
+	if err != nil {
+		t.Fatalf("ReadPluginDataNDJSON: %v", err)
+	}
+	if len(records) != 1 || records[0]["activityId"] != "two" {
+		t.Fatalf("records = %+v, want only two", records)
+	}
+}

internal/core/workspace/manager.go

@@ -40,6 +40,7 @@ const (
 
 // Workspace is a physical top-level workspace folder.
 type Workspace struct {
+	ID       string `json:"id"`
 	Name     string `json:"name"`
 	RootPath string `json:"rootPath"`
 }
@@ -66,6 +67,7 @@ type WorkspaceTemplate struct {
 // Metadata stores semantic workspace metadata that is not the source of truth
 // for whether the workspace exists.
 type Metadata struct {
+	WorkspaceID         string            `json:"workspaceId,omitempty"`
 	WorkspaceName       string            `json:"workspaceName"`
 	CreatedFromTemplate *TemplateSnapshot `json:"createdFromTemplate,omitempty"`
 	Features            map[string]bool   `json:"features,omitempty"`
@@ -74,6 +76,12 @@ type Metadata struct {
 	UpdatedAt           string            `json:"updatedAt,omitempty"`
 }
 
+const workspaceIdentityRelativePath = ".verstak/workspace.json"
+
+type workspaceIdentityMarker struct {
+	WorkspaceID string `json:"workspaceId"`
+}
+
 // MetadataPatch updates metadata fields without replacing unspecified fields.
 type MetadataPatch struct {
 	Features map[string]bool   `json:"features,omitempty"`
@@ -82,12 +90,20 @@ type MetadataPatch struct {
 
 // TrashResult describes a workspace moved into the internal trash area.
 type TrashResult struct {
+	WorkspaceID  string `json:"workspaceId"`
 	OriginalPath string `json:"originalPath"`
 	TrashPath    string `json:"trashPath"`
 	TrashID      string `json:"trashId"`
 	DeletedAt    string `json:"deletedAt"`
 }
 
+// WorkspaceIdentity identifies an existing top-level workspace independently of its path.
+type WorkspaceIdentity struct {
+	WorkspaceID string `json:"workspaceId"`
+	RootPath    string `json:"rootPath"`
+	State       string `json:"state"`
+}
+
 // WorkspaceNode is a compatibility shell view of a top-level workspace.
 // Path is deliberately not serialized; workspaceRootPath is derived from Name/ID.
 type WorkspaceNode struct {
@@ -301,7 +317,11 @@ func (m *Manager) ListWorkspaces() ([]Workspace, error) {
 		if !entry.IsDir() {
 			continue
 		}
-		workspaces = append(workspaces, Workspace{Name: name, RootPath: name})
+		workspaceID, err := ensureWorkspaceIdentity(filepath.Join(m.vaultDir, name))
+		if err != nil {
+			return nil, err
+		}
+		workspaces = append(workspaces, Workspace{ID: workspaceID, Name: name, RootPath: name})
 	}
 	sort.Slice(workspaces, func(i, j int) bool {
 		return strings.ToLower(workspaces[i].Name) < strings.ToLower(workspaces[j].Name)
@@ -309,6 +329,84 @@ func (m *Manager) ListWorkspaces() ([]Workspace, error) {
 	return workspaces, nil
 }
 
+// GetWorkspaceIdentity resolves the durable identity for an existing workspace.
+func (m *Manager) GetWorkspaceIdentity(name string) (WorkspaceIdentity, error) {
+	name = strings.TrimSpace(name)
+	if err := validateWorkspaceName(name); err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	full := filepath.Join(m.vaultDir, name)
+	if err := ensureExistingWorkspaceDir(full, name); err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	workspaceID, err := ensureWorkspaceIdentity(full)
+	if err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	return WorkspaceIdentity{WorkspaceID: workspaceID, RootPath: name, State: "active"}, nil
+}
+
+// ListWorkspaceIdentities returns durable identities and flags copied markers.
+func (m *Manager) ListWorkspaceIdentities() ([]WorkspaceIdentity, error) {
+	workspaces, err := m.ListWorkspaces()
+	if err != nil {
+		return nil, err
+	}
+	counts := make(map[string]int, len(workspaces))
+	for _, workspace := range workspaces {
+		counts[workspace.ID]++
+	}
+	identities := make([]WorkspaceIdentity, 0, len(workspaces))
+	for _, workspace := range workspaces {
+		state := "active"
+		if counts[workspace.ID] > 1 {
+			state = "duplicate"
+		}
+		identities = append(identities, WorkspaceIdentity{
+			WorkspaceID: workspace.ID,
+			RootPath:    workspace.RootPath,
+			State:       state,
+		})
+	}
+	return identities, nil
+}
+
+// RepairWorkspaceIdentity keeps the identity on one copied workspace and regenerates the other.
+func (m *Manager) RepairWorkspaceIdentity(keepName, regenerateName string) error {
+	keepName = strings.TrimSpace(keepName)
+	regenerateName = strings.TrimSpace(regenerateName)
+	if err := validateWorkspaceName(keepName); err != nil {
+		return err
+	}
+	if err := validateWorkspaceName(regenerateName); err != nil {
+		return err
+	}
+	if keepName == regenerateName {
+		return fmt.Errorf("workspace identity repair requires two workspaces")
+	}
+	keepPath := filepath.Join(m.vaultDir, keepName)
+	regeneratePath := filepath.Join(m.vaultDir, regenerateName)
+	if err := ensureExistingWorkspaceDir(keepPath, keepName); err != nil {
+		return err
+	}
+	if err := ensureExistingWorkspaceDir(regeneratePath, regenerateName); err != nil {
+		return err
+	}
+	keepID, err := ensureWorkspaceIdentity(keepPath)
+	if err != nil {
+		return err
+	}
+	regenerateID, err := ensureWorkspaceIdentity(regeneratePath)
+	if err != nil {
+		return err
+	}
+	if keepID != regenerateID {
+		return fmt.Errorf("workspaces do not share an identity")
+	}
+	_, err = writeWorkspaceIdentity(regeneratePath)
+	return err
+}
+
 // CreateWorkspace creates a top-level workspace folder and applies a template once.
 func (m *Manager) CreateWorkspace(name, templateID string) (Workspace, error) {
 	name = strings.TrimSpace(name)
@@ -339,11 +437,16 @@ func (m *Manager) CreateWorkspace(name, templateID string) (Workspace, error) {
 		}
 	}()
 
+	workspaceID, err := ensureWorkspaceIdentity(full)
+	if err != nil {
+		return Workspace{}, err
+	}
 	if err := applyTemplate(full, template); err != nil {
 		return Workspace{}, err
 	}
 	now := time.Now().UTC().Format(time.RFC3339Nano)
 	meta := Metadata{
+		WorkspaceID:   workspaceID,
 		WorkspaceName: name,
 		CreatedFromTemplate: &TemplateSnapshot{
 			TemplateID:      template.ID,
@@ -362,7 +465,82 @@ func (m *Manager) CreateWorkspace(name, templateID string) (Workspace, error) {
 	}
 
 	created = false
-	return Workspace{Name: name, RootPath: name}, nil
+	return Workspace{ID: workspaceID, Name: name, RootPath: name}, nil
+}
+
+func writeWorkspaceIdentity(workspacePath string) (string, error) {
+	workspaceID := uuid.NewString()
+	data, err := json.Marshal(workspaceIdentityMarker{WorkspaceID: workspaceID})
+	if err != nil {
+		return "", err
+	}
+	markerPath := filepath.Join(workspacePath, filepath.FromSlash(workspaceIdentityRelativePath))
+	if err := os.MkdirAll(filepath.Dir(markerPath), 0o755); err != nil {
+		return "", err
+	}
+	tmpPath := markerPath + ".tmp"
+	if err := os.WriteFile(tmpPath, data, 0o644); err != nil {
+		return "", err
+	}
+	if err := os.Rename(tmpPath, markerPath); err != nil {
+		_ = os.Remove(tmpPath)
+		return "", err
+	}
+	return workspaceID, nil
+}
+
+func ensureWorkspaceIdentity(workspacePath string) (string, error) {
+	workspaceID, err := readWorkspaceIdentity(workspacePath)
+	if os.IsNotExist(err) {
+		return writeWorkspaceIdentity(workspacePath)
+	}
+	if err != nil {
+		return "", err
+	}
+	return workspaceID, nil
+}
+
+func readWorkspaceIdentity(workspacePath string) (string, error) {
+	markerPath := filepath.Join(workspacePath, filepath.FromSlash(workspaceIdentityRelativePath))
+	data, err := os.ReadFile(markerPath)
+	if err != nil {
+		return "", err
+	}
+	var marker workspaceIdentityMarker
+	if err := json.Unmarshal(data, &marker); err != nil {
+		return "", err
+	}
+	if _, err := uuid.Parse(marker.WorkspaceID); err != nil {
+		return "", fmt.Errorf("invalid workspace identity: %w", err)
+	}
+	return marker.WorkspaceID, nil
+}
+
+// GetWorkspaceTrashIdentity reads a trashed workspace identity without restoring it.
+func (m *Manager) GetWorkspaceTrashIdentity(trashID string) (WorkspaceIdentity, error) {
+	trashID = strings.TrimSpace(trashID)
+	if err := validateWorkspaceTrashID(trashID); err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	trashDir := filepath.Join(m.vaultDir, ".verstak", "trash", "workspaces", trashID)
+	data, err := os.ReadFile(filepath.Join(trashDir, "metadata.json"))
+	if err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	var trashMeta struct {
+		OriginalPath string `json:"originalPath"`
+	}
+	if err := json.Unmarshal(data, &trashMeta); err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	if err := validateWorkspaceName(trashMeta.OriginalPath); err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	workspaceID, err := readWorkspaceIdentity(filepath.Join(trashDir, trashMeta.OriginalPath))
+	if err != nil {
+		return WorkspaceIdentity{}, err
+	}
+	return WorkspaceIdentity{WorkspaceID: workspaceID, RootPath: trashMeta.OriginalPath, State: "trashed"}, nil
 }
 
 // ListWorkspaceTemplates returns selectable built-ins in their presentation order.
@@ -456,6 +634,10 @@ func (m *Manager) TrashWorkspace(name string) (TrashResult, error) {
 	if err := ensureExistingWorkspaceDir(full, name); err != nil {
 		return TrashResult{}, err
 	}
+	workspaceID, err := ensureWorkspaceIdentity(full)
+	if err != nil {
+		return TrashResult{}, err
+	}
 
 	deletedAt := time.Now().UTC().Format(time.RFC3339Nano)
 	trashID := time.Now().UTC().Format("20060102T150405.000000000Z") + "-" + uuid.NewString()
@@ -468,7 +650,7 @@ func (m *Manager) TrashWorkspace(name string) (TrashResult, error) {
 		return TrashResult{}, err
 	}
 
-	result := TrashResult{OriginalPath: name, TrashPath: trashRel, TrashID: trashID, DeletedAt: deletedAt}
+	result := TrashResult{WorkspaceID: workspaceID, OriginalPath: name, TrashPath: trashRel, TrashID: trashID, DeletedAt: deletedAt}
 	trashMeta := map[string]string{
 		"originalPath": name,
 		"trashPath":    trashRel,
@@ -500,6 +682,83 @@ func (m *Manager) TrashWorkspace(name string) (TrashResult, error) {
 	return result, nil
 }
 
+// RestoreWorkspaceTrash restores a trashed workspace under targetName without changing its identity.
+func (m *Manager) RestoreWorkspaceTrash(trashID, targetName string) (Workspace, error) {
+	trashID = strings.TrimSpace(trashID)
+	targetName = strings.TrimSpace(targetName)
+	if err := validateWorkspaceTrashID(trashID); err != nil {
+		return Workspace{}, err
+	}
+	if err := validateWorkspaceName(targetName); err != nil {
+		return Workspace{}, err
+	}
+	trashDir := filepath.Join(m.vaultDir, ".verstak", "trash", "workspaces", trashID)
+	data, err := os.ReadFile(filepath.Join(trashDir, "metadata.json"))
+	if err != nil {
+		return Workspace{}, err
+	}
+	var trashMeta struct {
+		OriginalPath string `json:"originalPath"`
+	}
+	if err := json.Unmarshal(data, &trashMeta); err != nil {
+		return Workspace{}, err
+	}
+	if err := validateWorkspaceName(trashMeta.OriginalPath); err != nil {
+		return Workspace{}, err
+	}
+	payloadPath := filepath.Join(trashDir, trashMeta.OriginalPath)
+	if err := ensureExistingWorkspaceDir(payloadPath, trashMeta.OriginalPath); err != nil {
+		return Workspace{}, err
+	}
+	targetPath := filepath.Join(m.vaultDir, targetName)
+	if _, err := os.Lstat(targetPath); err == nil {
+		return Workspace{}, fmt.Errorf("conflict: %s", targetName)
+	} else if !os.IsNotExist(err) {
+		return Workspace{}, err
+	}
+	if err := os.Rename(payloadPath, targetPath); err != nil {
+		return Workspace{}, err
+	}
+	restored := true
+	defer func() {
+		if restored {
+			_ = os.Rename(targetPath, payloadPath)
+		}
+	}()
+	if err := moveIfExists(filepath.Join(trashDir, "workspace.metadata.json"), m.metadataPath(targetName)); err != nil {
+		return Workspace{}, err
+	}
+	workspaceID, err := ensureWorkspaceIdentity(targetPath)
+	if err != nil {
+		return Workspace{}, err
+	}
+	if err := os.RemoveAll(trashDir); err != nil {
+		return Workspace{}, err
+	}
+	restored = false
+	return Workspace{ID: workspaceID, Name: targetName, RootPath: targetName}, nil
+}
+
+func validateWorkspaceTrashID(trashID string) error {
+	if trashID == "" || strings.ContainsAny(trashID, `/\\`) || filepath.Clean(trashID) != trashID {
+		return fmt.Errorf("invalid workspace trash ID")
+	}
+	return nil
+}
+
+// PurgeWorkspaceTrash permanently removes a workspace trash entry.
+func (m *Manager) PurgeWorkspaceTrash(trashID string) error {
+	trashID = strings.TrimSpace(trashID)
+	if err := validateWorkspaceTrashID(trashID); err != nil {
+		return err
+	}
+	trashDir := filepath.Join(m.vaultDir, ".verstak", "trash", "workspaces", trashID)
+	if _, err := os.Stat(filepath.Join(trashDir, "metadata.json")); err != nil {
+		return err
+	}
+	return os.RemoveAll(trashDir)
+}
+
 // GetWorkspaceMetadata returns stored metadata or safe generic metadata.
 func (m *Manager) GetWorkspaceMetadata(name string) (Metadata, error) {
 	name = strings.TrimSpace(name)

internal/core/workspace/manager_test.go

@@ -292,6 +292,167 @@ func TestTrashWorkspaceMovesFolderToTrashAndRemovesFromList(t *testing.T) {
 	}
 }
 
+func TestCreateWorkspaceWritesDurableIdentityMarker(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	if _, err := m.CreateWorkspace("Client", "default"); err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+
+	markerPath := filepath.Join(vaultDir, "Client", ".verstak", "workspace.json")
+	data, err := os.ReadFile(markerPath)
+	if err != nil {
+		t.Fatalf("read identity marker: %v", err)
+	}
+	var marker map[string]string
+	if err := json.Unmarshal(data, &marker); err != nil {
+		t.Fatalf("decode identity marker: %v", err)
+	}
+	if marker["workspaceId"] == "" {
+		t.Fatalf("workspaceId = %q, want UUID", marker["workspaceId"])
+	}
+}
+
+func TestListWorkspacesKeepsIdentityAfterRename(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	created, err := m.CreateWorkspace("Client", "default")
+	if err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	if err := m.RenameWorkspace("Client", "Client-2026"); err != nil {
+		t.Fatalf("RenameWorkspace: %v", err)
+	}
+
+	workspaces, err := m.ListWorkspaces()
+	if err != nil {
+		t.Fatalf("ListWorkspaces: %v", err)
+	}
+	if len(workspaces) != 1 {
+		t.Fatalf("workspaces = %+v, want one", workspaces)
+	}
+	if workspaces[0].Name != "Client-2026" {
+		t.Fatalf("workspace name = %q, want Client-2026", workspaces[0].Name)
+	}
+	if workspaces[0].ID != created.ID {
+		t.Fatalf("workspace ID = %q, want %q", workspaces[0].ID, created.ID)
+	}
+}
+
+func TestListWorkspaceIdentitiesMarksCopiedMarkerAsDuplicate(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	if _, err := m.CreateWorkspace("Original", "default"); err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	if err := os.Mkdir(filepath.Join(vaultDir, "Copied"), 0o755); err != nil {
+		t.Fatalf("mkdir copied: %v", err)
+	}
+	originalMarker := filepath.Join(vaultDir, "Original", ".verstak", "workspace.json")
+	copiedMarker := filepath.Join(vaultDir, "Copied", ".verstak", "workspace.json")
+	if err := os.MkdirAll(filepath.Dir(copiedMarker), 0o755); err != nil {
+		t.Fatalf("mkdir copied marker: %v", err)
+	}
+	data, err := os.ReadFile(originalMarker)
+	if err != nil {
+		t.Fatalf("read original marker: %v", err)
+	}
+	if err := os.WriteFile(copiedMarker, data, 0o644); err != nil {
+		t.Fatalf("write copied marker: %v", err)
+	}
+
+	identities, err := m.ListWorkspaceIdentities()
+	if err != nil {
+		t.Fatalf("ListWorkspaceIdentities: %v", err)
+	}
+	if len(identities) != 2 {
+		t.Fatalf("identities = %+v, want two", identities)
+	}
+	for _, identity := range identities {
+		if identity.State != "duplicate" {
+			t.Fatalf("identity %+v state = %q, want duplicate", identity, identity.State)
+		}
+	}
+}
+
+func TestRepairWorkspaceIdentityRegeneratesCopiedMarker(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	if _, err := m.CreateWorkspace("Original", "default"); err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	if err := os.Mkdir(filepath.Join(vaultDir, "Copied"), 0o755); err != nil {
+		t.Fatalf("mkdir copied: %v", err)
+	}
+	originalMarker := filepath.Join(vaultDir, "Original", ".verstak", "workspace.json")
+	copiedMarker := filepath.Join(vaultDir, "Copied", ".verstak", "workspace.json")
+	if err := os.MkdirAll(filepath.Dir(copiedMarker), 0o755); err != nil {
+		t.Fatalf("mkdir copied marker: %v", err)
+	}
+	data, err := os.ReadFile(originalMarker)
+	if err != nil {
+		t.Fatalf("read original marker: %v", err)
+	}
+	if err := os.WriteFile(copiedMarker, data, 0o644); err != nil {
+		t.Fatalf("write copied marker: %v", err)
+	}
+
+	if err := m.RepairWorkspaceIdentity("Original", "Copied"); err != nil {
+		t.Fatalf("RepairWorkspaceIdentity: %v", err)
+	}
+	identities, err := m.ListWorkspaceIdentities()
+	if err != nil {
+		t.Fatalf("ListWorkspaceIdentities: %v", err)
+	}
+	if len(identities) != 2 || identities[0].State != "active" || identities[1].State != "active" {
+		t.Fatalf("identities after repair = %+v", identities)
+	}
+	if identities[0].WorkspaceID == identities[1].WorkspaceID {
+		t.Fatalf("repair kept duplicate ID %q", identities[0].WorkspaceID)
+	}
+}
+
+func TestRestoreWorkspaceTrashPreservesIdentity(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	created, err := m.CreateWorkspace("Client", "default")
+	if err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	trashed, err := m.TrashWorkspace("Client")
+	if err != nil {
+		t.Fatalf("TrashWorkspace: %v", err)
+	}
+	restored, err := m.RestoreWorkspaceTrash(trashed.TrashID, "Client-Restored")
+	if err != nil {
+		t.Fatalf("RestoreWorkspaceTrash: %v", err)
+	}
+	if restored.Name != "Client-Restored" || restored.ID != created.ID {
+		t.Fatalf("restored = %+v, want name Client-Restored and ID %q", restored, created.ID)
+	}
+	if _, err := os.Stat(filepath.Join(vaultDir, "Client-Restored", ".verstak", "workspace.json")); err != nil {
+		t.Fatalf("restored marker: %v", err)
+	}
+}
+
+func TestPurgeWorkspaceTrashRemovesPayload(t *testing.T) {
+	vaultDir := newVaultDir(t)
+	m := NewManager(vaultDir)
+	if _, err := m.CreateWorkspace("Client", "default"); err != nil {
+		t.Fatalf("CreateWorkspace: %v", err)
+	}
+	trashed, err := m.TrashWorkspace("Client")
+	if err != nil {
+		t.Fatalf("TrashWorkspace: %v", err)
+	}
+	if err := m.PurgeWorkspaceTrash(trashed.TrashID); err != nil {
+		t.Fatalf("PurgeWorkspaceTrash: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(vaultDir, ".verstak", "trash", "workspaces", trashed.TrashID)); !os.IsNotExist(err) {
+		t.Fatalf("workspace trash remains, stat err=%v", err)
+	}
+}
+
 func TestCreateAndRenameConflictsAreExplicit(t *testing.T) {
 	vaultDir := newVaultDir(t)
 	mustMkdir(t, filepath.Join(vaultDir, "Existing"))