feat: update README with enhanced descriptions and security features; refactor catastrophic guard checks and tool execution handling

src/view/chat.rs

@@ -69,8 +69,13 @@ pub fn draw_chat(frame: &mut Frame, area: Rect, state: &crate::app::state::rest:
             ),
         ]);
 
-        let content_str = if msg.content.is_empty() {
-            "(streaming...)".to_string()
+        let is_last = std::ptr::eq(msg, messages.last().unwrap());
+        let content_str = if msg.content.trim().is_empty() {
+            if is_last && state.turn_in_flight() {
+                "(streaming...)".to_string()
+            } else {
+                "(tool execution)".to_string()
+            }
         } else {
             msg.content.clone()
         };