feat: add internal ZCLAW kernel crates to git tracking

crates/zclaw-runtime/src/tool/builtin.rs

@@ -0,0 +1,21 @@
+//! Built-in tools
+
+mod file_read;
+mod file_write;
+mod shell_exec;
+mod web_fetch;
+
+pub use file_read::FileReadTool;
+pub use file_write::FileWriteTool;
+pub use shell_exec::ShellExecTool;
+pub use web_fetch::WebFetchTool;
+
+use crate::tool::{ToolRegistry, Tool};
+
+/// Register all built-in tools
+pub fn register_builtin_tools(registry: &mut ToolRegistry) {
+    registry.register(Box::new(FileReadTool::new()));
+    registry.register(Box::new(FileWriteTool::new()));
+    registry.register(Box::new(ShellExecTool::new()));
+    registry.register(Box::new(WebFetchTool::new()));
+}