M2 checklists: note kind + items backend + editor/card UI

- Migration 0006: notes.kind ('text'|'list') + note_items (text, checked,
  position). Item API: add/update(toggle)/delete/reorder; PATCH note kind; note
  responses include kind + items[] (merged in one query alongside labels).
- notes store: kind/items on Note, setKind/addItem/updateItem/deleteItem.
- NoteChecklist component (toggle/add/edit/delete items); rendered read-only-ish
  on cards (checkboxes toggle) and editable in the editor.
- Editor: convert text<->checklist (body lines become items on convert to list).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

frontend/src/stores/notes.ts

@@ -4,21 +4,31 @@ import { api } from "../api/client";
 import type { NoteColor } from "../notes/colors";
 
 export type NoteView = "active" | "archived" | "trash";
+export type NoteKind = "text" | "list";
 
 export interface NoteLabel {
   id: string;
   name: string;
 }
 
+export interface ChecklistItem {
+  id: string;
+  text: string;
+  checked: boolean;
+  position: number;
+}
+
 export interface Note {
   id: string;
   title: string | null;
   body: string;
   color: NoteColor;
+  kind: NoteKind;
   pinned: boolean;
   archived: boolean;
   trashed: boolean;
   labels: NoteLabel[];
+  items: ChecklistItem[];
   created_at: string | null;
   updated_at: string | null;
 }
@@ -76,7 +86,7 @@ export const useNotesStore = defineStore("notes", () => {
 
   async function mutate(
     id: string,
-    changes: Partial<Pick<Note, "title" | "body" | "color" | "pinned" | "archived">>,
+    changes: Partial<Pick<Note, "title" | "body" | "color" | "kind" | "pinned" | "archived">>,
   ): Promise<void> {
     reconcile(await api.patch<Note>(`/api/notes/${id}`, changes));
   }
@@ -84,12 +94,25 @@ export const useNotesStore = defineStore("notes", () => {
   const setPinned = (id: string, pinned: boolean) => mutate(id, { pinned });
   const setArchived = (id: string, archived: boolean) => mutate(id, { archived });
   const setColor = (id: string, color: NoteColor) => mutate(id, { color });
+  const setKind = (id: string, kind: NoteKind) => mutate(id, { kind });
   const saveEdit = (id: string, changes: { title: string; body: string; color: NoteColor }) => mutate(id, changes);
 
   async function setLabels(id: string, labelIds: string[]): Promise<void> {
     reconcile(await api.put<Note>(`/api/notes/${id}/labels`, { label_ids: labelIds }));
   }
 
+  async function addItem(id: string, text: string): Promise<void> {
+    reconcile(await api.post<Note>(`/api/notes/${id}/items`, { text }));
+  }
+
+  async function updateItem(id: string, itemId: string, changes: { text?: string; checked?: boolean }): Promise<void> {
+    reconcile(await api.patch<Note>(`/api/notes/${id}/items/${itemId}`, changes));
+  }
+
+  async function deleteItem(id: string, itemId: string): Promise<void> {
+    reconcile(await api.del<Note>(`/api/notes/${id}/items/${itemId}`));
+  }
+
   async function trash(id: string): Promise<void> {
     reconcile(await api.post<Note>(`/api/notes/${id}/trash`));
   }
@@ -114,8 +137,12 @@ export const useNotesStore = defineStore("notes", () => {
     setPinned,
     setArchived,
     setColor,
+    setKind,
     saveEdit,
     setLabels,
+    addItem,
+    updateItem,
+    deleteItem,
     trash,
     restore,
     deleteForever,