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_130.md

@@ -0,0 +1,26 @@
+# Task ID: 130
+
+**Title:** Task service with lifecycle state machine
+
+**Status:** pending
+
+**Dependencies:** 129
+
+**Priority:** medium
+
+**Description:** Create TaskService implementing the full task lifecycle with transition guards and event logging
+
+**Details:**
+
+Create src/mcpd/src/services/task.service.ts:
+1. Define VALID_TRANSITIONS map: { [fromState]: [allowedToStates] } based on PRD lifecycle diagram
+2. transition(id, toState, actorType, actorId, note): check transition is valid, call repo.transition, if success create TaskEvent, return result
+3. assign(id, agentId): set assigneeId
+4. recordVerdict(id, stage, agentId, commit, passed, summary, findings): create TaskVerdict, if failed transition back to in_progress
+5. accept(id, userId, note): transition to merged, trigger merge via GitProvider
+6. reject(id, userId, note): transition to in_progress
+7. reopenOnPostMergeFailure(id): transition merged→reopened
+
+**Test Strategy:**
+
+Unit tests: test all valid transitions succeed, test invalid transitions throw, test TaskEvent created on every transition, test verdict creation, test accept triggers merge.