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/mod.rs

@@ -21,21 +21,18 @@ mod vision;
 
 use std::future::Future;
 use std::pin::Pin;
+use std::sync::Arc;
 use std::time::Instant;
 
 fn default_timeout() -> u64 { 120 }
 
-/// Async tool handler function.
-/// Agent is None when called from contexts without an agent (MCP server, subconscious).
-pub type ToolHandler = fn(
+pub type ToolHandler = Arc<dyn Fn(
     Option<std::sync::Arc<super::Agent>>,
     serde_json::Value,
-) -> Pin<Box<dyn Future<Output = anyhow::Result<String>> + Send>>;
+) -> Pin<Box<dyn Future<Output = anyhow::Result<String>> + Send>>
+    + Send + Sync>;
 
-/// A tool with its definition and handler — single source of truth.
-/// Strings are static — the tool list JSON can be built without
-/// serialization by interpolating these directly.
-#[derive(Clone, Copy)]
+#[derive(Clone)]
 pub struct Tool {
     pub name: &'static str,
     pub description: &'static str,