WIP: Output tool via Arc<Mutex<Subconscious>>, ToolHandler to Arc<dyn Fn>

- ToolHandler changed to Arc<dyn Fn(...)> (supports closures)
- Subconscious wrapped in Arc<Mutex<>> on Mind
- init_output_tool() pushes output tool closure capturing the Arc
- Output removed from static memory_tools()
- Most tool handlers wrapped in Arc::new() but some have paren issues

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/tools/glob.rs

@@ -22,7 +22,7 @@ pub fn tool() -> super::Tool {
         name: "glob",
         description: "Find files matching a glob pattern. Returns file paths sorted by modification time (newest first).",
         parameters_json: r#"{"type":"object","properties":{"pattern":{"type":"string","description":"Glob pattern to match files (e.g. '**/*.rs')"},"path":{"type":"string","description":"Directory to search in (default: current directory)"}},"required":["pattern"]}"#,
-        handler: |_a, v| Box::pin(async move { glob_search(&v) }),
+        handler: Arc::new(|_a, v| Box::pin(async move { glob_search(&v)) }),
     }
 }