feat: expose plugin data storage API

src/plugin-api.test.ts

@@ -12,6 +12,8 @@ describe('VerstakPluginAPI contract', () => {
     expect(api.pluginId).toBe('verstak.platform-test');
     expect(typeof api.settings.read).toBe('function');
     expect(typeof api.settings.write).toBe('function');
+    expect(typeof api.storage.data.read).toBe('function');
+    expect(typeof api.storage.data.write).toBe('function');
     expect(typeof api.capabilities.list).toBe('function');
     expect(typeof api.commands.register).toBe('function');
     expect(typeof api.commands.execute).toBe('function');
@@ -190,6 +192,25 @@ describe('VerstakPluginAPI contract', () => {
     await expect(api.settings.read()).resolves.toEqual({ savedText: 'hello' });
   });
 
+  test('plugin data persists separately from settings in the mock API namespace', async () => {
+    const api = createMockPluginAPI('storage.plugin');
+
+    await api.settings.write('search-index', { source: 'settings' });
+    await api.storage.data.write('search-index', {
+      version: 1,
+      workspaceRootPath: 'Project',
+      entries: [{ path: 'Project/Docs/case.md' }],
+    });
+
+    await expect(api.storage.data.read('search-index')).resolves.toEqual({
+      version: 1,
+      workspaceRootPath: 'Project',
+      entries: [{ path: 'Project/Docs/case.md' }],
+    });
+    await expect(api.settings.read('search-index')).resolves.toEqual({ source: 'settings' });
+    await expect(api.storage.data.read('missing')).resolves.toEqual({});
+  });
+
   test('commands register, execute, and unregister', async () => {
     const api = createMockPluginAPI('cmd.plugin');
 

src/plugin-api.ts

@@ -22,6 +22,7 @@ import type {
 } from './types';
 
 export type PluginCommandArgs = Record<string, unknown>;
+export type PluginDataJSON = Record<string, unknown>;
 export type PluginCommandHandler = (
   args: PluginCommandArgs,
   declaration: PluginCommandDeclaration
@@ -96,6 +97,13 @@ export interface VerstakPluginAPI {
     writeAll(settings: PluginSettings): Promise<void>;
   };
 
+  storage: {
+    data: {
+      read(name: string): Promise<PluginDataJSON>;
+      write(name: string, data: PluginDataJSON): Promise<void>;
+    };
+  };
+
   capabilities: {
     has(capability: string): Promise<boolean>;
     get(capability: string): Promise<{ available: boolean; name?: string; pluginId?: string; status?: string }>;

src/test-utils.ts

@@ -52,6 +52,7 @@ export function createTestPluginState(overrides?: Partial<PluginState>): PluginS
  */
 export function createMockPluginAPI(pluginId = 'test.plugin', options: MockPluginAPIOptions = {}): VerstakPluginAPI {
   const settings: Record<string, unknown> = {};
+  const pluginData = new Map<string, Record<string, unknown>>();
   const commands = new Map<string, PluginCommandHandler>();
   const eventHandlers = new Map<string, Array<(event: any) => void>>();
   const files = new Map<string, { type: 'file' | 'folder'; content?: string; modifiedAt: string }>();
@@ -129,6 +130,14 @@ export function createMockPluginAPI(pluginId = 'test.plugin', options: MockPlugi
         Object.assign(settings, nextSettings);
       }),
     },
+    storage: {
+      data: {
+        read: vi.fn(async (name: string) => ({ ...(pluginData.get(name) || {}) })),
+        write: vi.fn(async (name: string, data: Record<string, unknown>) => {
+          pluginData.set(name, { ...(data || {}) });
+        }),
+      },
+    },
     capabilities: {
       has: vi.fn(async () => false),
       get: vi.fn(async (name: string) => ({ available: false, name })),