calendar: add todo edit command

Allow editing todo fields (due date, priority) in place via todoman,
instead of requiring delete + recreate. Updates all docs for consistency.

skills/calendar/scripts/cal_tool.py

@@ -10,6 +10,7 @@ Subcommands:
     python calendar.py reply [options]         # accept/decline/tentative
     python calendar.py todo add [options]      # create a VTODO task
     python calendar.py todo list [options]     # list pending tasks
+    python calendar.py todo edit [options]     # edit a task's fields
     python calendar.py todo complete [options] # mark task as done
     python calendar.py todo delete [options]   # remove a task
     python calendar.py todo check              # daily digest for cron
@@ -600,6 +601,58 @@ def cmd_todo_complete(args):
     _sync_calendar()
 
 
+def _find_todo(uid="", match=""):
+    """Find a single todo by UID or summary match. Returns (todoman_id, todo_dict)."""
+    todos = _todoman_list_json("--sort", "due")
+    if uid:
+        matches = [t for t in todos if uid in (t.get("uid") or "")]
+        if not matches:
+            print(f"Error: No todo with UID '{uid}'", file=sys.stderr)
+            sys.exit(1)
+    elif match:
+        matches = [t for t in todos if match in (t.get("summary") or "")]
+        if not matches:
+            print(f"Error: No todo matching '{match}'", file=sys.stderr)
+            sys.exit(1)
+        if len(matches) > 1:
+            print(f"Error: Multiple todos match '{match}':", file=sys.stderr)
+            for t in matches:
+                print(f"  - {t.get('summary')} (uid: {t.get('uid')})", file=sys.stderr)
+            sys.exit(1)
+    else:
+        print("Error: --uid or --match is required", file=sys.stderr)
+        sys.exit(1)
+    return matches[0]["id"], matches[0]
+
+
+def cmd_todo_edit(args):
+    """Edit a todo's fields via todoman."""
+    todo_id, matched = _find_todo(uid=args.uid, match=args.match)
+
+    # Build todoman edit command args
+    todo_args = []
+    changes = []
+
+    if args.due:
+        todo_args += ["--due", args.due]
+        changes.append(f"due -> {args.due}")
+    if args.priority:
+        todo_args += ["--priority", args.priority]
+        prio_label = PRIORITY_LABELS.get(PRIORITY_MAP.get(args.priority, 5), "中")
+        changes.append(f"priority -> {prio_label}")
+
+    if not changes:
+        print("Nothing to change. Specify at least one of --due, --priority.")
+        return
+
+    # Run todoman edit (non-interactive)
+    _run_todoman("edit", str(todo_id), "--no-interactive", *todo_args)
+    print(f"Updated todo: {matched.get('summary')}")
+    for c in changes:
+        print(f"  {c}")
+    _sync_calendar()
+
+
 def cmd_todo_delete(args):
     """Delete a todo via todoman."""
     if args.uid:
@@ -688,6 +741,13 @@ def main():
     comp_p.add_argument("--uid", default="", help="Todo UID")
     comp_p.add_argument("--match", default="", help="Fuzzy match on summary")
 
+    # todo edit
+    edit_p = todo_sub.add_parser("edit", help="Edit a todo's fields")
+    edit_p.add_argument("--uid", default="", help="Todo UID")
+    edit_p.add_argument("--match", default="", help="Fuzzy match on summary")
+    edit_p.add_argument("--due", default="", help="New due date (YYYY-MM-DD)")
+    edit_p.add_argument("--priority", default="", choices=["", "high", "medium", "low"], help="New priority")
+
     # todo delete
     del_p = todo_sub.add_parser("delete", help="Delete a todo")
     del_p.add_argument("--uid", default="", help="Todo UID")
@@ -709,6 +769,8 @@ def main():
             cmd_todo_list(args)
         elif args.todo_command == "complete":
             cmd_todo_complete(args)
+        elif args.todo_command == "edit":
+            cmd_todo_edit(args)
         elif args.todo_command == "delete":
             cmd_todo_delete(args)
         elif args.todo_command == "check":