release: validate the complete 0.15.0 branch snapshot

Account for concurrent composer, conversation-order, desktop-notification,
and Supervisor discussion changes in bilingual notes and feature matrices.
Correct the removed entity-writeback description in the companion article.

Align the configuration fixture with the default-on notification setting,
scope note-source UI queries and wait for completed actions, and preserve
all real Obsidian child-process checks with a 15-second scenario allowance.

Validation: frozen complete tree passed 5371 Linux tests with 51 skipped;
19 focused Windows tests, typecheck, lint, and release-note validation passed.
The older 5345-test Host result did not cover all concurrent branch changes
and is not treated as validation of this complete candidate.

src/main/obsidian/obsidian-service.test.ts

@@ -127,7 +127,7 @@ describe('offline packaged MCPVault', () => {
     expect(await call('list_directory', {})).toContain('smoke.md')
     expect(await readFile(join(vaultPath, 'smoke.md'), 'utf8')).toContain('status: verified')
     await call('delete_note', { path: 'smoke.md', confirmPath: 'smoke.md', trashMode: 'local' })
-  })
+  }, 15_000)
 
   it('does not launch for an already cancelled call', async () => {
     const start = vi.spyOn(StdioClientTransport.prototype, 'start')