feat: implement subagent tool gating and timeout mechanisms for enhanced security and performance

src/app/runtime/actions/mod.rs

@@ -894,6 +894,11 @@ fn archive_message(db: &Option<std::sync::Arc<std::sync::Mutex<rusqlite::Connect
 /// the agent gets stuck in a loop (e.g. an unachievable todo item).
 const MAX_TURN_STEPS: usize = 10000;
 
+/// Hard wall-clock timeout per agent turn (5 minutes). Prevents a single
+/// user turn from running indefinitely even if the step budget isn't
+/// exhausted (e.g. slow LLM responses, stuck tool calls).
+const MAX_TURN_TIMEOUT_MS: u64 = 300_000;
+
 /// Execute one full agent turn: stream the conversation to the LLM,
 /// handle tool calls, and loop until the LLM produces a non-tool response
 /// or runs out of unfinished todo items.
@@ -924,7 +929,11 @@ fn run_agent_turn(
     let mut msgs = messages.to_vec();
     let mut edits_this_turn = 0u32;
     let mut prev_shaped = false;
+    let turn_start_ms = std::time::Instant::now();
 
+    // Build system prompt components once and cache them for the entire turn
+    // instead of regenerating on every loop iteration (which walks the full
+    // workspace tree and reads all memory files each time).
     let tree_info = generate_workspace_tree(&tc.workspace_roots);
     let memory_section = build_memory_section(&tc.ctx.memory_dir);
     let system_text = format!(
@@ -941,6 +950,8 @@ fn run_agent_turn(
     }
 
     let mut turn_step = 0usize;
+    let mut todo_retry_count = 0usize;
+    const MAX_TODO_RETRIES: usize = 5;
 
     loop {
         turn_step += 1;
@@ -951,6 +962,13 @@ fn run_agent_turn(
                 MAX_TURN_STEPS,
             );
         }
+        if turn_start_ms.elapsed().as_millis() as u64 > MAX_TURN_TIMEOUT_MS {
+            anyhow::bail!(
+                "turn exceeded maximum duration ({}s) — aborting. \
+                 Use /compact or shorter prompts if the model needs more time.",
+                MAX_TURN_TIMEOUT_MS / 1000,
+            );
+        }
         let total_chars: usize = msgs.iter()
             .filter_map(|m| m.content.as_deref())
             .map(|c| c.len())
@@ -1049,10 +1067,18 @@ fn run_agent_turn(
                             }
                         }
                         if has_unfinished {
+                            todo_retry_count += 1;
+                            if todo_retry_count > MAX_TODO_RETRIES {
+                                anyhow::bail!(
+                                    "exhausted {} todo-retries — giving up on unfinished tasks. \
+                                     Edit todo.md manually or ask me to focus on specific items.",
+                                    MAX_TODO_RETRIES,
+                                );
+                            }
                             if let Ok(mut q) = events_q.lock() {
                                 q.push_back(TurnEvent::SystemNote {
                                     kind: "task_retry".to_string(),
-                                    message: format!("Network/API error: {}. Auto-retrying to finish tasks...", api_err),
+                                    message: format!("Network/API error: {}. Auto-retrying to finish tasks... (retry {}/{})", api_err, todo_retry_count, MAX_TODO_RETRIES),
                                 });
                             }
                             std::thread::sleep(std::time::Duration::from_secs(5));
@@ -1160,14 +1186,25 @@ fn run_agent_turn(
             }
 
             if has_unfinished {
-                let sys_text = "You stopped, but you still have unfinished tasks in todo.md (marked with '- [ ]'). You MUST continue working and use tools to finish them, or edit todo.md to mark them as done if they are finished.";
+                todo_retry_count += 1;
+                if todo_retry_count > MAX_TODO_RETRIES {
+                    if let Ok(mut q) = events_q.lock() {
+                        q.push_back(TurnEvent::SystemNote {
+                            kind: "task_retry".to_string(),
+                            message: format!("Giving up after {} retries — some todo items remain unfinished. Edit todo.md manually or ask again.", MAX_TODO_RETRIES),
+                        });
+                    }
+                    break;
+                }
+                let sys_text = format!("You stopped, but you still have unfinished tasks in todo.md (marked with '- [ ]'). You MUST continue working and use tools to finish them, or edit todo.md to mark them as done if they are finished. (Retry {}/{})", todo_retry_count, MAX_TODO_RETRIES);
+                let sys_text_clone = sys_text.clone();
                 let msg = ChatMessage::system(sys_text);
                 archive_message(&tc.db, &tc.session_id, &msg);
                 msgs.push(msg);
                 if let Ok(mut q) = events_q.lock() {
                     q.push_back(TurnEvent::SystemNote {
                         kind: "task_retry".to_string(),
-                        message: sys_text.to_string(),
+                        message: sys_text_clone,
                     });
                 }
                 continue;