merge: AgentProject membership — the junction is now load-bearing

Merges feat/agent-project-membership (task 166/152). An agent can finally join
many projects: membership routes, per-membership role and optional brain
override, chat resolving context from the membership, and CLI attach-agent /
detach-agent / get memberships. The legacy Agent.projectId fallback is kept for
this release as the schema comment promises.

Conflict resolved in main.ts: that branch added its RBAC case to
mapUrlToPermission inline, while this branch had extracted the function to
middleware/url-permission.ts so it could be tested. Kept the extraction and
ported the case into it — joining a team is `edit:agents:<name>`, not
`create:agents`, which is the authority to mint a whole agent.

Also fixes something the extraction makes possible. security.test.ts contained a
hand-copied reproduction of mapUrlToPermission, because main.ts self-invokes
main() and nothing in it was importable. A security test asserting against a
copy stops testing the system the moment the real one changes, and this copy had
already drifted. It now imports the real function; all 18 assertions still pass,
against the code that actually runs.

Local: build clean, workspace 2550 passed, lint unchanged at 794 errors.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4wNHWf7xSwnZCWpJcyv9p

.taskmaster/tasks/task_063.md

@@ -0,0 +1,68 @@
+# Task ID: 63
+
+**Title:** Add unit tests for prompt priority and link CRUD
+
+**Status:** done
+
+**Dependencies:** 40 ✓, 41 ✓
+
+**Priority:** high
+
+**Description:** Create comprehensive unit tests for all prompt CRUD operations with the new priority and linkTarget fields.
+
+**Details:**
+
+1. Add tests in `/src/mcpd/tests/services/prompt-service.test.ts`:
+   ```typescript
+   describe('Prompt Priority', () => {
+     it('creates prompt with explicit priority', async () => {
+       const prompt = await service.createPrompt({ ...data, priority: 8 });
+       expect(prompt.priority).toBe(8);
+     });
+     
+     it('uses default priority 5 when not specified', async () => {
+       const prompt = await service.createPrompt(data);
+       expect(prompt.priority).toBe(5);
+     });
+     
+     it('validates priority range 1-10', async () => {
+       await expect(service.createPrompt({ ...data, priority: 11 }))
+         .rejects.toThrow();
+     });
+     
+     it('updates priority', async () => {
+       const updated = await service.updatePrompt(id, { priority: 3 });
+       expect(updated.priority).toBe(3);
+     });
+   });
+   
+   describe('Prompt Links', () => {
+     it('creates linked prompt', async () => {
+       const prompt = await service.createPrompt({
+         ...data,
+         linkTarget: 'project/server:uri'
+       });
+       expect(prompt.linkTarget).toBe('project/server:uri');
+     });
+     
+     it('rejects invalid link format', async () => {
+       await expect(service.createPrompt({
+         ...data,
+         linkTarget: 'invalid'
+       })).rejects.toThrow();
+     });
+     
+     it('linkTarget is immutable on update', async () => {
+       // linkTarget not accepted in update schema
+     });
+   });
+   ```
+
+**Test Strategy:**
+
+This task IS the test implementation. Verify:
+- All priority CRUD tests pass
+- All link CRUD tests pass
+- Validation tests cover edge cases
+- Tests use proper mocking patterns
+- Coverage meets project standards