fix(marketplace): preserve release sync semantics

tests/unit/coding-plugin-composition.test.ts

@@ -186,6 +186,48 @@ describe('coding plugin bounded product service', () => {
     });
   });
 
+  it('projects a Marketplace Skill owner collision as unavailable', async () => {
+    const root = await mkdtemp(path.join(tmpdir(), 'makelore-plugin-collision-'));
+    roots.push(root);
+    await createCodingProjectMetadata(root, { now: '2026-08-29T00:00:00.000Z' });
+    const definition = {
+      ...DATA_SERVICE_PLUGIN_DEFINITION,
+      id: 'makelore.data-service-shadow', displayName: 'Data Service Shadow',
+      description: 'Conflicting package', requiresBackend: false, runtimeKind: 'skill_only' as const,
+      acquisitionMode: 'user_acquired' as const, releaseId: 'release-shadow',
+      provenance: { source: 'marketplace' as const, packageRoot: 'C:/packages/release-shadow' },
+      adapterId: '', operations: [], tools: [],
+      skills: [{ id: 'data-service', entryPath: 'skills/data-service/SKILL.md', grants: [] }],
+      surfaces: {},
+    };
+    const service = createCodingProjectPluginService({
+      projects: { getProject: vi.fn().mockResolvedValue({ id: 'local-a', path: root }) },
+      projectPlugins: {
+        getEnabledPluginIds: vi.fn().mockResolvedValue([definition.id]), setEnabled: vi.fn(),
+      },
+      policyClient: {
+        refresh: vi.fn(),
+        getState: () => ({ status: 'unavailable' as const, revision: 0, lastVerifiedAt: null, catalog: null }),
+      },
+      adapters: [], definitions: [definition],
+      effectiveResolver: {
+        resolve: vi.fn().mockResolvedValue({
+          accountSessionId: 'account-a\u00001', projectId: 'local-a',
+          pluginReleaseIds: [], effectiveSkillIds: [], skillEntries: [],
+          toolDefinitions: [], runtimePolicies: [],
+          unavailableReasons: [{
+            pluginId: definition.id, code: 'skill_owner_conflict',
+            message: 'Plugin Skill ID conflicts with an existing owner',
+          }],
+        }),
+      } as never,
+    });
+
+    await expect(service.list('local-a')).resolves.toMatchObject({
+      items: [{ id: definition.id, enabled: true, state: 'unavailable' }],
+    });
+  });
+
   it('projects the exact three capabilities and fourteen mixed-policy operations', async () => {
     const root = await mkdtemp(path.join(tmpdir(), 'makelore-plugin-policy-join-'));
     roots.push(root);