fix: improve kiro-cli state detection and add Refresh method

- IsBusy now checks /proc/PID/stat for process state (R/D = busy)
  when no child processes exist, fixing false idle detection
- Add Refresh() to Session interface to re-detect state on demand

internal/backend/backend.go

@@ -31,6 +31,9 @@ type Session interface {
 	// State returns current state ("starting", "idle", "running", "error: ...", "exited")
 	State() string
 
+	// Refresh retries startup if in error state, or refreshes state detection
+	Refresh(ctx context.Context) error
+
 	// Send sends a prompt and returns the response
 	// Blocks until response is complete
 	Send(ctx context.Context, prompt string) (string, error)

internal/backend/tmux/session.go

@@ -475,3 +475,23 @@ func (s *Session) Close() error {
 	s.state = "exited"
 	return nil
 }
+
+// Refresh re-detects state based on process activity
+func (s *Session) Refresh(ctx context.Context) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.state == "exited" {
+		return nil
+	}
+
+	// Check if process is busy
+	busy := s.stateInspector != nil && s.stateInspector.IsBusy(s.pid)
+	if busy {
+		s.state = "running"
+	} else {
+		s.state = "idle"
+	}
+	debug.Log("[session %s] refresh: state=%s", s.id, s.state)
+	return nil
+}

internal/backends/kirocli.go

@@ -46,7 +46,27 @@ func (i *kiroStateInspector) IsBusy(panePID int) bool {
 	}
 	// Check if kiro-cli-chat has any children (tool executions)
 	cmd := exec.Command("pgrep", "-P", fmt.Sprintf("%d", chatPID))
-	return cmd.Run() == nil
+	if cmd.Run() == nil {
+		return true // has children = busy
+	}
+	// No children - check if process is actively running (not sleeping waiting for input)
+	return isProcessActive(chatPID)
+}
+
+// isProcessActive checks if a process is doing work (not blocked waiting for input)
+func isProcessActive(pid int) bool {
+	data, err := os.ReadFile(fmt.Sprintf("/proc/%d/stat", pid))
+	if err != nil {
+		return false
+	}
+	fields := strings.Fields(string(data))
+	if len(fields) < 3 {
+		return false
+	}
+	state := fields[2]
+	// R = running, D = disk sleep (I/O), both indicate active work
+	// S = interruptible sleep (waiting for input) = idle
+	return state == "R" || state == "D"
 }
 
 // kiroCommands implements command handling for kiro-cli