Add local JSON daemon and route TUI/CLI through it.

A per-DataDir background process owns ticket JSON, history, and sync so
multiple TUI instances stay consistent; MCP token APIs are ready for phase 2.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/daemon/api/history_handlers.go

@@ -0,0 +1,37 @@
+package api
+
+import (
+	"net/http"
+)
+
+func (s *Server) handleHistoryStatus(w http.ResponseWriter, r *http.Request) {
+	_ = r
+	writeJSON(w, http.StatusOK, map[string]any{
+		"canUndo":      s.history.CanUndo(),
+		"canRedo":      s.history.CanRedo(),
+		"lastUndoName": s.history.LastUndoName(),
+		"lastRedoName": s.history.LastRedoName(),
+	})
+}
+
+func (s *Server) handleUndo(w http.ResponseWriter, r *http.Request) {
+	_ = r
+	name := s.history.LastUndoName()
+	if err := s.history.Undo(); err != nil {
+		writeErr(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	s.notify("")
+	writeJSON(w, http.StatusOK, map[string]string{"name": name})
+}
+
+func (s *Server) handleRedo(w http.ResponseWriter, r *http.Request) {
+	_ = r
+	name := s.history.LastRedoName()
+	if err := s.history.Redo(); err != nil {
+		writeErr(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	s.notify("")
+	writeJSON(w, http.StatusOK, map[string]string{"name": name})
+}