fix(config) : disable rate_limiter config requiring uninstalled component

The mcp_auth rate limiter requires symfony/rate-limiter which is not
installed. Renamed to .disabled until the MCP stack is ready.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

config/packages/rate_limiter.yaml.disabled

@@ -0,0 +1,6 @@
+framework:
+    rate_limiter:
+        mcp_auth:
+            policy: sliding_window
+            limit: 5
+            interval: '1 minute'