fix: close marketplace client review findings

tests/unit/plugin-marketplace-store.test.ts

@@ -70,6 +70,53 @@ describe('plugin Marketplace store', () => {
     expect(store.getState().library?.items[0].title).toBe('Acquired');
   });
 
+  it('keeps the newest same-account Library read when an older response completes last', async () => {
+    const first = deferred<MarketplaceLibraryProjection>();
+    const second = deferred<MarketplaceLibraryProjection>();
+    const readLibrary = vi.fn()
+      .mockImplementationOnce(() => first.promise)
+      .mockImplementationOnce(() => second.promise);
+    const store = createPluginMarketplaceStore({ readLibrary });
+    store.getState().activateAccount('account-a');
+    const oldest = store.getState().loadLibrary();
+    const newest = store.getState().loadLibrary();
+    second.resolve(projection('newest')); await newest;
+    first.resolve(projection('oldest')); await oldest;
+    expect(store.getState().library?.items[0].title).toBe('newest');
+  });
+
+  it('does not let an older mutation response overwrite a newer mutation for another plugin', async () => {
+    const make = (pluginId: string, title: string): MarketplaceLibraryProjection => ({
+      library: {
+        total: 1, stale: false, fetchedAt: 1,
+        items: [{
+          pluginId, title, summary: title, category: 'tools', acquisition: 'free',
+          acquisitionMode: 'user_acquired', catalogStatus: 'active', runtimeStatus: 'enabled',
+          acquiredAt: '2026-08-28T00:00:00Z', removedAt: null, stableVersion: '1.0.0', betaVersion: null,
+        }],
+      },
+      installations: [],
+    });
+    for (const order of ['a-then-b', 'b-then-a'] as const) {
+      const a = deferred<MarketplaceLibraryProjection>();
+      const b = deferred<MarketplaceLibraryProjection>();
+      const store = createPluginMarketplaceStore({
+        acquire: vi.fn((pluginId: string) => pluginId === 'makelore.a' ? a.promise : b.promise),
+      });
+      store.getState().activateAccount('account-a');
+      const aRequest = store.getState().acquire('makelore.a');
+      const bRequest = store.getState().acquire('makelore.b');
+      if (order === 'a-then-b') {
+        a.resolve(make('makelore.a', 'A older')); await aRequest;
+        b.resolve(make('makelore.b', 'B newer')); await bRequest;
+      } else {
+        b.resolve(make('makelore.b', 'B newer')); await bRequest;
+        a.resolve(make('makelore.a', 'A older')); await aRequest;
+      }
+      expect(store.getState().library?.items[0].title).toBe('B newer');
+    }
+  });
+
   it('calls only the selected state mutation', async () => {
     const acquire = vi.fn().mockResolvedValue(projection('Acquired'));
     const install = vi.fn().mockResolvedValue({ status: 'installed', pluginId: 'makelore.notes', version: '1.0.0' });
@@ -86,4 +133,21 @@ describe('plugin Marketplace store', () => {
     expect(install).toHaveBeenCalledOnce();
     expect(setProjectEnabled).not.toHaveBeenCalled();
   });
+
+  it('projects a bounded installation failure on the affected My Plugins entry', async () => {
+    const error = Object.assign(new Error('Release signature is invalid'), {
+      code: 'plugin_signature_invalid',
+    });
+    const store = createPluginMarketplaceStore({
+      install: vi.fn().mockRejectedValue(error),
+    });
+    store.getState().activateAccount('account-a');
+
+    await expect(store.getState().install('makelore.notes')).rejects.toBe(error);
+    expect(store.getState().installations['makelore.notes']).toMatchObject({
+      status: 'unavailable',
+      pluginId: 'makelore.notes',
+      reason: 'plugin_signature_invalid: Release signature is invalid',
+    });
+  });
 });