fix(tools): deny council tools globally via permission system

The config.tools boolean false wasn't blocking plugin-registered tools.
Add prepare_council_prompt, council_finalize, athena_council to global
permission deny — same pattern as task: deny. Per-agent allow on
athena/athena-junior overrides the global deny.

src/plugin-handlers/tool-config-handler.ts

@@ -152,5 +152,8 @@ export function applyToolConfig(params: {
     external_directory: "allow",
     ...(params.config.permission as Record<string, unknown>),
     task: "deny",
+    prepare_council_prompt: "deny",
+    council_finalize: "deny",
+    athena_council: "deny",
   };
 }