Add test and update documentation for heartbeat tool factory

Co-authored-by: yiwang <142937+yiwang@users.noreply.github.com>

Author: Copilot

CLAUDE.md

@@ -94,6 +94,8 @@ Mobile crate uses `default-features = false, features = ["embeddings-openai"]` 
 
 **Tool safety split:** `Agent::new()` creates safe tools only (memory_search, memory_get, web_fetch, web_search). CLI injects dangerous tools (bash, read_file, write_file, edit_file) via `agent.extend_tools(create_cli_tools())`. Server agents intentionally only get safe tools.
 
+**Heartbeat tool injection:** `HeartbeatRunner` in core accepts an optional `ToolFactory` callback to extend the agent with additional tools. CLI daemon provides `create_cli_tools` factory so heartbeat can perform file operations and execute commands. Without the factory, heartbeat runs with safe tools only.
+
 **Custom tool sets:** `Agent::new_with_tools()` replaces all tools — used by Gen mode for its own Bevy tools (spawn_entity, modify_entity, etc.).
 
 **Thread safety:** Agent is not `Send+Sync` due to SQLite. Use `AgentHandle` (`Arc<tokio::sync::Mutex<Agent>>`) for mobile/server. HTTP handler uses `spawn_blocking`.

crates/core/src/heartbeat/runner.rs

@@ -435,4 +435,17 @@ mod tests {
         assert!(noon >= start && noon <= end);
         assert!(!(midnight >= start && midnight <= end));
     }
+
+    #[test]
+    fn test_tool_factory_type_signature() {
+        // Verify that the ToolFactory type can be constructed with a closure
+        // that matches create_cli_tools signature
+        let _factory: ToolFactory = Box::new(|_config: &Config| {
+            // Simulate returning CLI tools
+            Ok(Vec::new())
+        });
+
+        // This test just verifies the type signature compiles correctly
+        // Actual tool creation is tested in integration tests
+    }
 }