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_087.md

@@ -0,0 +1,48 @@
+# Task ID: 87
+
+**Title:** Add proxyModel Field to Project Schema
+
+**Status:** cancelled
+
+**Dependencies:** None
+
+**Priority:** high
+
+**Description:** Extend the Project database schema and API to support proxyModel field and proxyModelOverrides for per-content-type configuration.
+
+**Details:**
+
+Update `src/db/prisma/schema.prisma`:
+
+```prisma
+model Project {
+  // ... existing fields
+  proxyModel          String?   @default("default")
+  proxyModelOverrides Json?     // { prompts: { "prompt-name": "model" }, toolResults: { "server/tool": "model" } }
+}
+```
+
+Run `npx prisma migrate dev --name add_proxymodel_field`.
+
+Update `src/mcpd/src/routes/projects.ts` to include the new fields in CRUD operations.
+
+Update `src/cli/src/commands/get.ts` and `describe.ts` to display proxyModel.
+
+Update `src/cli/src/commands/patch.ts` to support `--set proxyModel=<name>`.
+
+**Test Strategy:**
+
+Database migration test: verify migration applies cleanly. API tests: verify proxyModel field is returned in project GET, can be updated via PATCH. CLI tests: verify `mcpctl describe project <name>` shows proxyModel.
+
+## Subtasks
+
+### 87.1. Minimal placeholder subtask
+
+**Status:** pending  
+**Dependencies:** None  
+
+This task requires complete rewrite before expansion.
+
+**Details:**
+
+Task 87 has been marked as DO NOT EXPAND and needs to be completely rewritten first. No subtasks should be generated until the task is properly redefined.