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/bash.rs

@@ -37,7 +37,7 @@ pub fn tool() -> super::Tool {
         name: "bash",
         description: "Execute a bash command and return its output. Use for git operations, building, running tests, and other terminal tasks.",
         parameters_json: r#"{"type":"object","properties":{"command":{"type":"string","description":"The bash command to execute"},"timeout_secs":{"type":"integer","description":"Timeout in seconds (default 120)"}},"required":["command"]}"#,
-        handler: |_a, v| Box::pin(async move { run_bash(&v).await }),
+        handler: Arc::new(|_a, v| Box::pin(async move { run_bash(&v).await })),
     }
 }