feat(tui): token metrics aggregation, plan overlay, tool reasoning, clar dismissal

#295 — include narration_llm tokens in changes-panel aggregate count
#296 — execution plan overlay (Ctrl+P in-session)
#298 — surface reasoning/CoT on tool-call turns in output view
#265 — dismiss clarification modal when answered externally (session.resumed)

apps/tui-go/internal/app/key.go

@@ -31,6 +31,7 @@ const (
 	keyCtrlR
 	keyCtrlU
 	keyCtrlX
+	keyCtrlP
 	keyCtrlUp
 	keyCtrlDown
 	keyOther
@@ -99,6 +100,8 @@ func toKeyMsg(p tea.KeyPressMsg) keyMsg {
 				out.Type = keyCtrlC
 			case 'd':
 				out.Type = keyCtrlD
+			case 'p':
+				out.Type = keyCtrlP
 			case 'j':
 				out.Type = keyCtrlJ
 			case 'r':