verstak-desktop/docs/MILESTONE_6B_PLAN.md

Milestone 6b - Open/Edit Provider Registry + Workbench Routing Skeleton

This milestone adds the minimal infrastructure layer for open/edit routing before Files UI, Notes UI, or editor implementation starts. It does not implement those plugins and does not add a concrete core-owned Markdown editor.

Existing Architecture Found

Path	Section/title	Summary
../verstak-docs/00_README.md	Main architecture invariant	Core does not know concrete notes, file manager, or markdown editor features. It owns vault, plugin runtime, capability registry, contribution points, permissions, settings, events, storage, and UI shell.
../verstak-docs/01_Product_Vision.md	What is not in core / platform goal	Markdown editor, file manager, preview, and notes workflow are plugins. Users should be able to replace the markdown editor or install multiple editors.
../verstak-docs/02_Platform_Architecture.md	UI Shell / Capability Registry	UI Shell knows contribution points, not concrete note editor or file preview implementations. Files plugin checks editor/viewer capabilities instead of depending on official.markdown-editor.
../verstak-docs/03_Repositories.md	Repository split	verstak-desktop is Core Platform + UI Shell and does not contain mandatory notes, file manager, or markdown editor modules. Official plugins live separately.
../verstak-docs/04_Plugin_System.md	Goal / capabilities instead of plugin names / contribution points	Notes, file manager, editor, and viewer are plugin functions. The docs explicitly reject requires: ["official.markdown-editor"] and prefer optionalRequires: ["editor.text.markdown"].
../verstak-docs/05_Official_Plugins.md	official.files / official.notes / official.markdown-editor	Files optionally depends on editor/viewer capabilities. Markdown editor provides editor.text, editor.text.markdown, and editor.note.markdown, and must not own note storage or depend directly on official.notes.
../verstak-docs/06_Migration_Strategy.md	Do not / Definition of Done	Do not make notes/files/editor mandatory core parts. The platform transition is done only when notes/files/editor/preview/activity work as plugins.
docs/NOTES_FILES_PLUGIN_PLAN.md	Canonical Notes Model	Notes are ordinary Markdown files in canonical Notes/ folders. No lowercase notes, no .verstak/notes, no plugin-data note content, no UUID-only filenames.
docs/NOTES_FILES_PLUGIN_PLAN.md	Files Service Model	Files Core is raw vault file access and does not understand note semantics. Milestone 6a exposes safe text file methods and defers UI, watcher, binary streaming, external editor, and restore.
docs/PLUGIN_RUNTIME.md	Contribution Points / Bundled Frontend Plugin API	Current runtime hosts views/sidebar/settings/commands and exposes plugin-scoped Files API. fileActions, noteActions, contextMenuEntries, search/activity/status bar entries are registered but not hosted.
internal/core/contribution/registry.go	Contribution registry	Registry has the established contribution points and now extends that model with openProviders.
internal/core/plugin/plugin.go	Manifest contributions	Plugin manifest types now include openProviders alongside existing contribution points.
frontend/src/lib/shell/WorkbenchHost.svelte and frontend/src/lib/plugin-host/PluginBundleHost.svelte	Frontend plugin host	Workbench mounts the selected provider component by plugin id and component id. It remains generic and does not know a concrete editor.
frontend/src/lib/plugin-host/VerstakPluginAPI.js	Plugin API	Bundled plugins can call api.workbench.openResource() and api.workbench.editResource() in addition to settings, capabilities, events, commands, and Files API.
../verstak-sdk/src/types.ts and ../verstak-sdk/schemas/manifest.json	SDK contribution contracts	SDK types/schema define openProviders, OpenResourceRequest, provider supports, and files.* permissions.

What Matches The Desired Model

• Files/Notes/Editor are already documented as plugins, not core modules.
• Official plugins are expected to use the same runtime as community plugins.
• Files plugin is already documented as capability-driven, not hard-wired to a markdown editor.
• Markdown editor is already documented as replaceable via capabilities.
• Notes are already documented as Markdown files under canonical Notes/ folders, without .verstak/notes, UUID note entities, or a second storage truth.
• Desktop code has no hardcoded Markdown editor component.
• Existing plugin host can mount arbitrary plugin components, which is enough foundation for an editor provider host.

Contradictions Found

• docs/NOTES_FILES_PLUGIN_PLAN.md still said Files Core API/capability/permissions were unavailable, while later sections and code show Milestone 6a implemented them.
• ../verstak-docs/05_Official_Plugins.md calls notes "first-class Verstak entities". That is acceptable only as UI semantics; implementation must not create a separate note storage entity.
• ../verstak-docs/05_Official_Plugins.md lists "Open externally" as a Files fallback. External open remains deferred and must not enter Milestone 6b.
• ../verstak-sdk/schemas/manifest.json previously did not include files.read, files.write, or files.delete in the permissions enum, while SDK TS types, desktop permissions, and official platform-test manifest already used them. Milestone 6b resolves this 6a contract cleanup item.

Missing Before 6b

• openProviders contribution point.
• OpenResourceRequest contract.
• Workbench open/edit routing API for Files/Notes plugins.
• Provider selection model using resource kind, extension/mime, notes context, user preference, provider priority, deterministic fallback, and disabled provider fallback.
• User preferences for default text editor provider, default markdown editor provider, and default notes-context markdown editor provider.
• Host slot/tab that mounts the selected provider component with an open resource request.
• Tests for provider registration, selection, preferences, disabled provider fallback, and notes-context routing.

Added In 6b

• contributes.openProviders in SDK schema/types and desktop manifest structs.
• Desktop contribution registry support for registering, replacing, listing, and unregistering open providers.
• OpenResourceRequest, OpenResourceContext, OpenResourceResult, and opened-resource state in the Workbench routing skeleton.
• Provider selection by resource kind, extension/mime, generic-text, generic-markdown, or notes-markdown context, user preference, priority, deterministic pluginId/providerId fallback, and active plugin filtering.
• workbench.open policy permission for plugins that request Workbench routing.
• Draft app settings preferences for default text, markdown, and notes-context markdown providers.
• api.workbench.openResource() and api.workbench.editResource() exposed to frontend plugin bundles.
• Minimal Workbench host that mounts the selected provider component from the selected provider plugin.
• no-provider fallback state when no matching provider exists.
• platform-test diagnostic open provider used only to prove routing.

Decision

Open/edit provider should be an extension of the existing contribution registry, not a parallel system. It should add openProviders beside views, commands, fileActions, and noteActions.

Capabilities remain useful for broad availability and degraded mode, but they are too coarse for choosing between multiple providers. Provider selection needs a declarative provider contribution with supports, priority, and component id.

Correct Notes Model

• Notes are a contextual view over ordinary Markdown files under canonical Notes/ folders.
• .md inside Notes/ opens through the selected markdown editor with notes-context.
• .md outside Notes/ opens through the selected markdown editor in generic markdown mode.
• Plain text opens through the selected text editor provider in generic-text context.
• Files and Notes call open/edit resource; neither embeds a concrete editor.
• Editor provider selection belongs to Workbench/provider registry.
• No .verstak/notes, no UUID note entities, no second truth separate from the .md file.

Minimal Infrastructure Changes

1. Add openProviders to SDK manifest/schema/types.
2. Add openProviders to desktop plugin manifest structs and contribution registry.
3. Add OpenResourceRequest and provider support match types.
4. Add Workbench/provider selection service with deterministic rules.
5. Add user preferences for defaultTextEditorProvider, defaultMarkdownEditorProvider, and defaultNotesMarkdownEditorProvider.
6. Add frontend host plumbing so Workbench can mount the selected plugin component.
7. Fix verstak-sdk/schemas/manifest.json permissions enum for files.*.

Proposed Milestone 6b Scope

In scope:

• Contribution/types/schema support for openProviders.
• Workbench openResource/editResource routing API.
• Provider selection with notes context and user preferences.
• Minimal host tab/slot for provider component mounting.
• Diagnostic provider plugin contribution sufficient to prove routing.
• Tests for routing, provider selection, disabled fallback, and notes-context markdown.

Out of scope:

• Full Files UI feature set.
• Full Notes UI feature set.
• Full editor implementation.
• Real default editor plugin (Milestone 6c).
• Files plugin open/edit integration.
• Notes plugin open/edit integration.
• Hardcoded core Markdown editor.
• Watcher/sync/binary streaming/external editor.
• Sidecar/security boundary.
• Large rewrite.

6b-fix: Infrastructure Gaps Closed

Post-review fixes before Milestone 6c:

• Added openProviders to verstak-sdk/schemas/contributions.json contribution points.
• Added provider matching tests: text/markdown preference, MIME matching, extension case-insensitivity, multiple supports entries, kind mismatch.
• Added disabled provider exclusion test in api/app_test.go.
• Fixed SDK build.sh/test.sh to detect incomplete node_modules.
• Documented disabled provider lifecycle: contributions remain in registry until ReloadPlugins; activeOpenProviders() filters disabled/unloaded at request time.
• Installed Playwright browsers for E2E tests.