feat: expose permanent trash deletion in sdk

src/plugin-api.test.ts

@@ -35,6 +35,7 @@ describe('VerstakPluginAPI contract', () => {
     expect(typeof api.files.trash).toBe('function');
     expect(typeof api.files.listTrash).toBe('function');
     expect(typeof api.files.restoreTrash).toBe('function');
+    expect(typeof api.files.deleteTrash).toBe('function');
     expect(typeof api.files.openExternal).toBe('function');
     expect(typeof api.files.showInFolder).toBe('function');
     expect(typeof api.workbench.openResource).toBe('function');
@@ -359,6 +360,11 @@ describe('VerstakPluginAPI contract', () => {
       expect.objectContaining({ relativePath: 'PlatformTest/image.bin', type: 'file' }),
     ]));
     await expect(api.files.listTrash()).resolves.toEqual([]);
+
+    const permanentlyDeleted = await api.files.trash('PlatformTest/two.txt');
+    await expect(api.files.deleteTrash(permanentlyDeleted.trashId)).resolves.toBeUndefined();
+    await expect(api.files.listTrash()).resolves.toEqual([]);
+    await expect(api.files.readText('PlatformTest/two.txt')).rejects.toThrow('not-found: PlatformTest/two.txt');
   });
 
   test('files mock rejects non-canonical and reserved paths', async () => {

src/plugin-api.ts

@@ -157,6 +157,7 @@ export interface VerstakPluginAPI {
     trash(relativePath: string): Promise<TrashResult>;
     listTrash(): Promise<TrashEntry[]>;
     restoreTrash(trashId: string, options?: RestoreTrashOptions): Promise<string>;
+    deleteTrash(trashId: string): Promise<void>;
     openExternal(relativePath: string): Promise<void>;
     showInFolder(relativePath: string): Promise<void>;
   };

src/test-utils.ts

@@ -348,6 +348,12 @@ export function createMockPluginAPI(pluginId = 'test.plugin', options: MockPlugi
         if (index >= 0) trashEntries.splice(index, 1);
         return target;
       }),
+      deleteTrash: vi.fn(async (trashId: string) => {
+        const index = trashEntries.findIndex((item) => item.trashId === trashId);
+        if (index < 0) throw new Error(`not-found: trash entry ${trashId}`);
+        trashEntries.splice(index, 1);
+        trashPayloads.delete(trashId);
+      }),
       openExternal: vi.fn(async (relativePath: string) => {
         const path = normalizePath(relativePath);
         if (!files.has(path)) throw new Error(`not-found: ${path}`);