Release v1.3.0: AI feature flag and MCP server

- Add AI_FEATURES_ENABLED config flag to gate AI/natural-language features
- Conditionally register /api/ask router based on AI_FEATURES_ENABLED
- Add GET /api/config/features endpoint for frontend feature detection
- Update frontend to hide Ask panel when AI features are disabled
- Implement standalone MCP server (backend/mcp_server.py) with tools:
  * search_events, get_event, get_summary, ask
- Add mcp dependency to requirements.txt
- Update .env.example, AGENTS.md, and ROADMAP.md
- Bump VERSION to 1.3.0

backend/routes/config.py

@@ -1,4 +1,5 @@
 from config import (
+    AI_FEATURES_ENABLED,
     AUTH_CLIENT_ID,
     AUTH_ENABLED,
     AUTH_SCOPE,
@@ -18,3 +19,10 @@ def auth_config():
         "scope": AUTH_SCOPE,
         "redirect_uri": None,  # frontend uses window.location.origin by default
     }
+
+
+@router.get("/config/features")
+def features_config():
+    return {
+        "ai_features_enabled": AI_FEATURES_ENABLED,
+    }