Allow moving tickets between projects with P.

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

internal/ticket/jsonstore.go

@@ -146,6 +146,73 @@ func (s *JSONStore) Update(t Ticket) error {
 	return s.writeUnlocked(t.ProjectID, tickets)
 }
 
+// Move relocates a ticket to another project directory.
+func (s *JSONStore) Move(id, toProjectID string) (Ticket, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if id == "" {
+		return Ticket{}, fmt.Errorf("ticket id is required")
+	}
+	if toProjectID == "" {
+		return Ticket{}, fmt.Errorf("projectId is required")
+	}
+
+	projects, err := os.ReadDir(filepath.Join(s.dataDir, "projects"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Ticket{}, fmt.Errorf("ticket %s: not found", id)
+		}
+		return Ticket{}, fmt.Errorf("list projects: %w", err)
+	}
+
+	var found Ticket
+	fromProject := ""
+	for _, p := range projects {
+		if !p.IsDir() {
+			continue
+		}
+		tickets, err := s.readUnlocked(p.Name())
+		if err != nil {
+			return Ticket{}, err
+		}
+		for i, t := range tickets {
+			if t.ID != id {
+				continue
+			}
+			found = t
+			fromProject = p.Name()
+			tickets = append(tickets[:i], tickets[i+1:]...)
+			if err := s.writeUnlocked(fromProject, tickets); err != nil {
+				return Ticket{}, err
+			}
+			break
+		}
+		if fromProject != "" {
+			break
+		}
+	}
+	if fromProject == "" {
+		return Ticket{}, fmt.Errorf("ticket %s: not found", id)
+	}
+
+	found.ProjectID = toProjectID
+	found.UpdatedAt = time.Now().UTC()
+
+	if err := os.MkdirAll(s.projectPath(toProjectID), 0o755); err != nil {
+		return Ticket{}, fmt.Errorf("create project dir: %w", err)
+	}
+	dest, err := s.readUnlocked(toProjectID)
+	if err != nil {
+		return Ticket{}, err
+	}
+	dest = append(dest, found)
+	if err := s.writeUnlocked(toProjectID, dest); err != nil {
+		return Ticket{}, err
+	}
+	return found, nil
+}
+
 // Delete removes a ticket by ID from its project's file.
 func (s *JSONStore) Delete(id string) error {
 	s.mu.Lock()