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_051.md

@@ -0,0 +1,54 @@
+# Task ID: 51
+
+**Title:** Implement keyword extraction from tool calls
+
+**Status:** done
+
+**Dependencies:** None
+
+**Priority:** medium
+
+**Description:** Create a service that extracts keywords from tool names and arguments for the intercept fallback path when clients skip begin_session.
+
+**Details:**
+
+1. Create `/src/mcplocal/src/services/keyword-extractor.service.ts`:
+   ```typescript
+   export class KeywordExtractorService {
+     extractKeywords(toolName: string, args: Record<string, any>): string[] {
+       const keywords: string[] = [];
+       
+       // Extract from tool name (split on / and -)
+       // e.g., "home-assistant/get_entities" -> ["home", "assistant", "get", "entities"]
+       keywords.push(...this.extractFromName(toolName));
+       
+       // Extract from argument values
+       // e.g., { domain: "light", entity_id: "light.kitchen" } -> ["light", "kitchen"]
+       keywords.push(...this.extractFromArgs(args));
+       
+       // Deduplicate and sanitize
+       return [...new Set(keywords.map(k => this.sanitize(k)))];
+     }
+     
+     private sanitize(keyword: string): string {
+       // Remove special characters, lowercase, limit length
+       return keyword.toLowerCase().replace(/[^a-z0-9]/g, '').slice(0, 50);
+     }
+   }
+   ```
+
+2. Handle various argument types: strings, arrays, nested objects
+
+3. Prevent injection by sanitizing extracted keywords
+
+**Test Strategy:**
+
+- Unit test: Extracts keywords from tool name with /
+- Unit test: Extracts keywords from tool name with -
+- Unit test: Extracts keywords from string argument values
+- Unit test: Extracts keywords from array argument values
+- Unit test: Handles nested object arguments
+- Unit test: Sanitizes special characters
+- Unit test: Deduplicates keywords
+- Unit test: Handles empty arguments
+- Unit test: Limits keyword length to prevent abuse