fix(coding): remediate ML-07 plugin authority

tests/unit/coding-plugins-store.test.ts

@@ -55,4 +55,60 @@ describe('coding plugins store', () => {
     await store.getState().load('other-project');
     expect(store.getState().dataService).toBeNull();
   });
+
+  it('commits only the latest project load success or error', async () => {
+    const pending = new Map<string, {
+      resolve: (value: ReturnType<typeof projection>) => void;
+      reject: (reason: Error) => void;
+    }>();
+    const list = vi.fn((projectId: string) => new Promise<ReturnType<typeof projection>>((resolve, reject) => {
+      pending.set(projectId, { resolve, reject });
+    }));
+    const store = createCodingPluginsStore({ list });
+
+    const first = store.getState().load('project-a');
+    const second = store.getState().load('project-b');
+    pending.get('project-b')?.resolve(projection(false, 'project-b'));
+    await second;
+    pending.get('project-a')?.resolve(projection(false, 'project-a'));
+    await first;
+    expect(store.getState()).toMatchObject({
+      projectId: 'project-b', loadState: 'ready', error: null,
+    });
+
+    const third = store.getState().load('project-a');
+    const fourth = store.getState().load('project-b');
+    pending.get('project-b')?.resolve(projection(false, 'project-b'));
+    await fourth;
+    pending.get('project-a')?.reject(new Error('late project-a failure'));
+    await expect(third).rejects.toThrow('late project-a failure');
+    expect(store.getState()).toMatchObject({
+      projectId: 'project-b', loadState: 'ready', error: null,
+    });
+  });
+
+  it('retains ready Data Service usage when enabling an existing instance', async () => {
+    const readyProjection = projection(true);
+    readyProjection.items[0] = {
+      ...readyProjection.items[0], state: 'ready', backend: { status: 'ready' },
+    };
+    const existing = {
+      instance_id: 'instance-1', project_id: 'cloud-project', collections: ['todos'],
+      usage: { document_count: 3, total_bytes: 128 },
+      limits: { max_collections: 20, max_documents: 1000, max_total_bytes: 20971520, max_document_bytes: 65536, list_default_limit: 50, list_max_limit: 100, list_max_data_bytes: 1048576, mutations_per_minute: 120 },
+      created_at: '2026-08-27T00:00:00Z', updated_at: '2026-08-27T00:00:00Z',
+    };
+    const inspectDataService = vi.fn().mockResolvedValue({
+      success: true, status: 200, code: null, error: null, retryable: false, data: existing,
+    });
+    const store = createCodingPluginsStore({
+      setEnabled: vi.fn().mockResolvedValue(readyProjection), inspectDataService,
+    });
+
+    await store.getState().setEnabled('local-project', 'makelore.data-service', true);
+
+    expect(inspectDataService).toHaveBeenCalledOnce();
+    expect(store.getState().dataService).toEqual(existing);
+    expect(store.getState().projection).toEqual(readyProjection);
+  });
 });