feat(todo): richer metadata (tags, startDate, files) + edit/detail dialog

ToDoアイテムのメタデータを拡充し、編集/詳細ダイアログを追加。

- lib/db/migrations/003_todo_tags.sql: todo_items に tags 列を追加
- TodoRepository/TodoService: startDate(従来ハードコードNULL)とtagsをcreate/updateで永続化、fileIdsで添付紐付け(トランザクション)、deleteItemで添付クリーンアップ、getItem/getItemAttachments を追加
- API: GET /todos/items/[itemId] ({item, attachments}) を追加、POST/PATCH で startDate/tags/fileIds を受理、PATCH は null(クリア)と undefined(更新しない)を区別
- UI: TodoDialog(タイトル/説明/担当/優先度/開始日/期限/タグ/添付を編集、完了日時・タイムスタンプは読み取り専用)、KanbanBoard のカードクリックでダイアログを開きメタデータを表示
- MilestoneRepository の todo マッピングに tags を追加し as never キャストを修正
- docs/functional-design.md に tags / file_assets.source / attachments テーブルを追記

components/todo/KanbanBoard.tsx

@@ -2,6 +2,8 @@
 
 import { useCallback, useState, type DragEvent } from 'react';
 import type { TodoColumn, TodoItem } from '@/lib/types';
+import type { ProjectMemberWithUser } from '@/repositories/ProjectMemberRepository';
+import { TodoDialog } from '@/components/todo/TodoDialog';
 
 const PRIORITY_COLORS: Record<string, string> = {
   high: 'bg-red-100 text-red-700',
@@ -13,13 +15,16 @@ export function KanbanBoard({
   projectId,
   columns,
   initialItems,
+  members,
 }: {
   projectId: number;
   columns: TodoColumn[];
   initialItems: TodoItem[];
+  members: ProjectMemberWithUser[];
 }) {
   const [items, setItems] = useState<TodoItem[]>(initialItems);
   const [draggingId, setDraggingId] = useState<number | null>(null);
+  const [selectedItem, setSelectedItem] = useState<TodoItem | null>(null);
 
   const reload = useCallback(async () => {
     const res = await fetch(`/api/projects/${projectId}/todos/items`);
@@ -44,7 +49,7 @@ export function KanbanBoard({
       setDraggingId(null);
       return;
     }
-    // 楽観的にローカル更新したあとAPIで移動
+    // 楽観的にローカル更新したあとAPIで移動(失敗時は再取得で巻き戻す)
     setItems((prev) =>
       prev.map((i) => (i.id === itemId ? { ...i, columnId: column.id } : i))
     );
@@ -52,7 +57,9 @@ export function KanbanBoard({
       method: 'PATCH',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ columnId: column.id, orderIndex: 0 }),
-    }).then(() => reload());
+    })
+      .catch(() => undefined)
+      .finally(() => reload());
     setDraggingId(null);
   }
 
@@ -91,48 +98,99 @@ export function KanbanBoard({
               {column.name} ({colItems.length})
             </h2>
             <ul className="space-y-2">
-              {colItems.map((item) => (
-                <li
-                  key={item.id}
-                  draggable
-                  onDragStart={(e) => onDragStart(e, item.id)}
-                  className={`cursor-grab rounded border bg-white p-2 shadow-sm ${
-                    draggingId === item.id ? 'opacity-50' : ''
-                  } ${item.completedAt ? 'opacity-60 line-through' : ''}`}
-                  data-testid={`todo-card-${item.id}`}
-                >
-                  <div className="flex items-start justify-between gap-2">
-                    <span className="text-sm">{item.title}</span>
-                    <button
-                      type="button"
-                      onClick={() => toggleComplete(item.id)}
-                      className="text-xs text-blue-600 hover:underline"
-                      data-testid={`todo-complete-${item.id}`}
-                    >
-                      {item.completedAt ? '戻す' : '完了'}
-                    </button>
-                  </div>
-                  <div className="mt-1 flex gap-1">
-                    <span
-                      className={`rounded px-1.5 py-0.5 text-xs ${
-                        PRIORITY_COLORS[item.priority] ?? PRIORITY_COLORS.normal
-                      }`}
-                    >
-                      {item.priority}
-                    </span>
-                    {item.dueDate && (
-                      <span className="text-xs text-gray-500">
-                        期限: {item.dueDate}
+              {colItems.map((item) => {
+                const tags = item.tags
+                  ?.split(',')
+                  .map((t) => t.trim())
+                  .filter(Boolean);
+                const assignee = members.find(
+                  (m) => m.user.id === item.assigneeId
+                );
+                return (
+                  <li
+                    key={item.id}
+                    draggable
+                    onDragStart={(e) => onDragStart(e, item.id)}
+                    onClick={() => setSelectedItem(item)}
+                    className={`cursor-grab rounded border bg-white p-2 shadow-sm ${
+                      draggingId === item.id ? 'opacity-50' : ''
+                    } ${item.completedAt ? 'opacity-60 line-through' : ''}`}
+                    data-testid={`todo-card-${item.id}`}
+                  >
+                    <div className="flex items-start justify-between gap-2">
+                      <span
+                        className="text-sm hover:text-blue-600 hover:underline"
+                        data-testid={`todo-open-${item.id}`}
+                      >
+                        {item.title}
                       </span>
+                      <button
+                        type="button"
+                        onClick={(e) => {
+                          e.stopPropagation();
+                          toggleComplete(item.id);
+                        }}
+                        className="text-xs text-blue-600 hover:underline"
+                        data-testid={`todo-complete-${item.id}`}
+                      >
+                        {item.completedAt ? '戻す' : '完了'}
+                      </button>
+                    </div>
+                    <div className="mt-1 flex flex-wrap items-center gap-1">
+                      <span
+                        className={`rounded px-1.5 py-0.5 text-xs ${
+                          PRIORITY_COLORS[item.priority] ??
+                          PRIORITY_COLORS.normal
+                        }`}
+                      >
+                        {item.priority}
+                      </span>
+                      {item.dueDate && (
+                        <span className="text-xs text-gray-500">
+                          期限: {item.dueDate}
+                        </span>
+                      )}
+                      {item.startDate && (
+                        <span className="text-xs text-gray-400">
+                          開始: {item.startDate}
+                        </span>
+                      )}
+                      {assignee && (
+                        <span className="text-xs text-gray-500">
+                          @{assignee.user.name}
+                        </span>
+                      )}
+                    </div>
+                    {tags && tags.length > 0 && (
+                      <div className="mt-1 flex flex-wrap gap-1">
+                        {tags.map((t) => (
+                          <span
+                            key={t}
+                            className="rounded bg-gray-100 px-1.5 py-0.5 text-[10px] text-gray-600"
+                          >
+                            {t}
+                          </span>
+                        ))}
+                      </div>
                     )}
-                  </div>
-                </li>
-              ))}
+                  </li>
+                );
+              })}
             </ul>
             <NewTaskInput onAdd={(title) => addTask(column.id, title)} />
           </section>
         );
       })}
+
+      {selectedItem && (
+        <TodoDialog
+          projectId={projectId}
+          item={selectedItem}
+          members={members}
+          onClose={() => setSelectedItem(null)}
+          onSaved={reload}
+        />
+      )}
     </div>
   );
 }

components/todo/TodoDialog.tsx

@@ -0,0 +1,311 @@
+'use client';
+
+import { useEffect, useRef, useState } from 'react';
+import type { AttachmentView, TodoItem, TodoPriority } from '@/lib/types';
+import type { ProjectMemberWithUser } from '@/repositories/ProjectMemberRepository';
+import { AttachmentList } from '@/components/files/AttachmentList';
+import {
+  AttachmentPicker,
+  type AttachmentPickerHandle,
+} from '@/components/files/AttachmentPicker';
+
+const PRIORITIES: TodoPriority[] = ['low', 'normal', 'high'];
+
+function parseTags(tags: string | null): string[] {
+  if (!tags) return [];
+  return tags
+    .split(',')
+    .map((t) => t.trim())
+    .filter((t) => t.length > 0);
+}
+
+/**
+ * ToDo編集/詳細ダイアログ。
+ * カードクリックで開き、タイトル/説明/担当/優先度/開始日/期限/タグ/添付を
+ * 編集・閲覧できる。完了日(完了時刻)・作成/更新日時は読み取り専用で表示。
+ */
+export function TodoDialog({
+  projectId,
+  item,
+  members,
+  onClose,
+  onSaved,
+}: {
+  projectId: number;
+  item: TodoItem;
+  members: ProjectMemberWithUser[];
+  onClose: () => void;
+  onSaved: () => void | Promise<void>;
+}) {
+  const [title, setTitle] = useState(item.title);
+  const [description, setDescription] = useState(item.description ?? '');
+  const [assigneeId, setAssigneeId] = useState<string>(
+    item.assigneeId ? String(item.assigneeId) : ''
+  );
+  const [priority, setPriority] = useState<TodoPriority>(item.priority);
+  const [startDate, setStartDate] = useState(item.startDate ?? '');
+  const [dueDate, setDueDate] = useState(item.dueDate ?? '');
+  const [tags, setTags] = useState(item.tags ?? '');
+  const [attachments, setAttachments] = useState<AttachmentView[]>([]);
+  const [current, setCurrent] = useState<TodoItem>(item);
+  const [loading, setLoading] = useState(true);
+  const [saving, setSaving] = useState(false);
+  const [pickerLoading, setPickerLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const pickerRef = useRef<AttachmentPickerHandle>(null);
+
+  // 開封時に最新のアイテム+添付を取得
+  useEffect(() => {
+    let alive = true;
+    setLoading(true);
+    fetch(`/api/projects/${projectId}/todos/items/${item.id}`)
+      .then((res) => (res.ok ? res.json() : null))
+      .then((data) => {
+        if (!alive || !data) return;
+        const fetched = data.item as TodoItem;
+        setTitle(fetched.title);
+        setDescription(fetched.description ?? '');
+        setAssigneeId(fetched.assigneeId ? String(fetched.assigneeId) : '');
+        setPriority(fetched.priority);
+        setStartDate(fetched.startDate ?? '');
+        setDueDate(fetched.dueDate ?? '');
+        setTags(fetched.tags ?? '');
+        setAttachments((data.attachments as AttachmentView[]) ?? []);
+        setCurrent(fetched);
+      })
+      .catch(() => undefined)
+      .finally(() => alive && setLoading(false));
+    return () => {
+      alive = false;
+    };
+  }, [projectId, item.id]);
+
+  useEffect(() => {
+    function onKey(e: KeyboardEvent) {
+      if (e.key === 'Escape') onClose();
+    }
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [onClose]);
+
+  async function onSave() {
+    setSaving(true);
+    setError(null);
+    const fileIds = pickerRef.current?.getFileIds() ?? [];
+    const res = await fetch(
+      `/api/projects/${projectId}/todos/items/${item.id}`,
+      {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          title,
+          description,
+          assigneeId: assigneeId ? Number(assigneeId) : null,
+          priority,
+          startDate: startDate || null,
+          dueDate: dueDate || null,
+          tags: tags || null,
+          fileIds,
+        }),
+      }
+    );
+    setSaving(false);
+    if (res.ok) {
+      pickerRef.current?.clear();
+      await onSaved();
+      onClose();
+    } else {
+      const b = (await res.json().catch(() => null)) as {
+        error?: { message?: string };
+      } | null;
+      setError(b?.error?.message ?? '保存に失敗しました');
+    }
+  }
+
+  const tagList = parseTags(tags);
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex items-start justify-center bg-black/40 p-4"
+      onClick={onClose}
+      data-testid="todo-dialog-backdrop"
+    >
+      <div
+        className="mt-8 w-full max-w-xl rounded-lg bg-white shadow-xl"
+        onClick={(e) => e.stopPropagation()}
+        role="dialog"
+        aria-modal="true"
+        aria-label={`ToDo ${item.title} の編集`}
+        data-testid="todo-dialog"
+      >
+        <div className="flex items-center justify-between border-b p-4">
+          <h2 className="text-lg font-bold text-gray-800">ToDoの編集</h2>
+          <button
+            type="button"
+            onClick={onClose}
+            className="rounded p-1 text-gray-400 hover:bg-gray-100 hover:text-gray-600"
+            aria-label="閉じる"
+            data-testid="todo-dialog-close"
+          >
+            ×
+          </button>
+        </div>
+
+        {loading ? (
+          <p className="p-6 text-sm text-gray-400">読み込み中...</p>
+        ) : (
+          <div className="max-h-[70vh] space-y-3 overflow-y-auto p-4">
+            <div>
+              <label className="block text-sm font-medium">タイトル</label>
+              <input
+                type="text"
+                value={title}
+                onChange={(e) => setTitle(e.target.value)}
+                className="mt-1 w-full rounded border px-3 py-2"
+                data-testid="todo-title"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium">説明</label>
+              <textarea
+                value={description}
+                onChange={(e) => setDescription(e.target.value)}
+                className="mt-1 min-h-[80px] w-full rounded border px-3 py-2"
+                data-testid="todo-description"
+              />
+            </div>
+            <div className="grid grid-cols-2 gap-3">
+              <div>
+                <label className="block text-sm font-medium">担当者</label>
+                <select
+                  value={assigneeId}
+                  onChange={(e) => setAssigneeId(e.target.value)}
+                  className="mt-1 w-full rounded border px-3 py-2"
+                  data-testid="todo-assignee"
+                >
+                  <option value="">未割当</option>
+                  {members.map((m) => (
+                    <option key={m.user.id} value={String(m.user.id)}>
+                      {m.user.name}
+                    </option>
+                  ))}
+                </select>
+              </div>
+              <div>
+                <label className="block text-sm font-medium">優先度</label>
+                <select
+                  value={priority}
+                  onChange={(e) => setPriority(e.target.value as TodoPriority)}
+                  className="mt-1 w-full rounded border px-3 py-2"
+                  data-testid="todo-priority"
+                >
+                  {PRIORITIES.map((p) => (
+                    <option key={p} value={p}>
+                      {p}
+                    </option>
+                  ))}
+                </select>
+              </div>
+            </div>
+            <div className="grid grid-cols-2 gap-3">
+              <div>
+                <label className="block text-sm font-medium">開始日</label>
+                <input
+                  type="date"
+                  value={startDate}
+                  onChange={(e) => setStartDate(e.target.value)}
+                  className="mt-1 w-full rounded border px-3 py-2"
+                  data-testid="todo-start-date"
+                />
+              </div>
+              <div>
+                <label className="block text-sm font-medium">
+                  期限 (deadline)
+                </label>
+                <input
+                  type="date"
+                  value={dueDate}
+                  onChange={(e) => setDueDate(e.target.value)}
+                  className="mt-1 w-full rounded border px-3 py-2"
+                  data-testid="todo-due-date"
+                />
+              </div>
+            </div>
+            <div>
+              <label className="block text-sm font-medium">
+                タグ (カンマ区切り)
+              </label>
+              <input
+                type="text"
+                value={tags}
+                onChange={(e) => setTags(e.target.value)}
+                placeholder="frontend, urgent"
+                className="mt-1 w-full rounded border px-3 py-2"
+                data-testid="todo-tags"
+              />
+              {tagList.length > 0 && (
+                <div className="mt-1 flex flex-wrap gap-1">
+                  {tagList.map((t) => (
+                    <span
+                      key={t}
+                      className="rounded bg-gray-100 px-2 py-0.5 text-xs text-gray-600"
+                    >
+                      {t}
+                    </span>
+                  ))}
+                </div>
+              )}
+            </div>
+
+            <div>
+              <p className="mb-1 text-sm font-medium">添付ファイル</p>
+              {attachments.length > 0 ? (
+                <AttachmentList attachments={attachments} />
+              ) : (
+                <p className="text-xs text-gray-400">添付なし</p>
+              )}
+              <div className="mt-2">
+                <AttachmentPicker
+                  ref={pickerRef}
+                  projectId={projectId}
+                  onLoadingChange={setPickerLoading}
+                />
+              </div>
+            </div>
+
+            <div className="space-y-1 border-t pt-3 text-xs text-gray-500">
+              <p>完了日時: {current.completedAt ?? '未完了'}</p>
+              <p>作成: {current.createdAt}</p>
+              <p>更新: {current.updatedAt}</p>
+            </div>
+
+            {error && (
+              <p className="text-sm text-red-600" role="alert">
+                {error}
+              </p>
+            )}
+          </div>
+        )}
+
+        <div className="flex justify-end gap-2 border-t p-4">
+          <button
+            type="button"
+            onClick={onClose}
+            className="rounded border px-4 py-2 text-sm text-gray-600 hover:bg-gray-100"
+          >
+            キャンセル
+          </button>
+          <button
+            type="button"
+            onClick={onSave}
+            disabled={saving || pickerLoading || loading}
+            className="rounded bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700 disabled:opacity-50"
+            data-testid="todo-save"
+          >
+            {saving ? '保存中...' : '保存'}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}