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_104.md

@@ -0,0 +1,67 @@
+# Task ID: 104
+
+**Title:** Extend Traffic Events for ProxyModel Processing
+
+**Status:** cancelled
+
+**Dependencies:** 80 ✓
+
+**Priority:** medium
+
+**Description:** Add new traffic event types for proxymodel processing: content_original, content_transformed, stage timing, cache hits/misses.
+
+**Details:**
+
+Modify `src/mcplocal/src/http/traffic.ts`:
+
+```typescript
+export type TrafficEventType = 
+  | 'client_request'
+  | 'client_response'
+  | 'upstream_request'
+  | 'upstream_response'
+  | 'client_notification'
+  // New proxymodel events:
+  | 'content_original'
+  | 'content_transformed'
+  | 'stage_executed'
+  | 'stage_cache_hit'
+  | 'stage_cache_miss';
+
+export interface ContentOriginalEvent {
+  eventType: 'content_original';
+  sessionId: string;
+  contentType: 'prompt' | 'toolResult';
+  sourceName: string;
+  content: string;
+  charCount: number;
+}
+
+export interface ContentTransformedEvent {
+  eventType: 'content_transformed';
+  sessionId: string;
+  contentType: 'prompt' | 'toolResult';
+  sourceName: string;
+  content: string;
+  charCount: number;
+  proxyModel: string;
+  stages: string[];
+  durationMs: number;
+}
+
+export interface StageExecutedEvent {
+  eventType: 'stage_executed';
+  sessionId: string;
+  stageName: string;
+  inputChars: number;
+  outputChars: number;
+  durationMs: number;
+  cacheHit: boolean;
+}
+```
+
+Emit these events from the pipeline executor.
+
+**Test Strategy:**
+
+Unit tests: events emitted at correct points in pipeline execution, event payloads contain correct data, cache hit/miss events distinguish correctly. Integration test with inspector showing new events.