feat(admin): クラス・課題に俯瞰ダッシュボードと復元ファセットを追加

docs/admin/README.md

@@ -17,7 +17,7 @@
 ### セクション（3 ドメイン）
 
 1. **みんなの課題**（S3 #1083）: 通報キュー（多い順）/ 全投稿一覧 / 詳細（ページ・画像・クレジット）/ 非公開⇄再公開（2 段階確認・audit）
-2. **クラス・課題**（S4 #1084）: 全クラス検索（参加コード完全一致・名前部分一致）/ 詳細（参加・提出カウント）/ アーカイブ切替 / **期限切れクラスの復元**（ddb-archive スナップショット検索 → dry-run プラン → 実行。EPIC #1049 の CLI `bin/restore-classroom.ts` の UI 後継）
+2. **クラス・課題**（S4 #1084 + 俯瞰ダッシュボード）: 3 タブ構成 — ①**俯瞰ダッシュボード**（作成の推移・内容の充実度・テーマ傾向 + みんなの課題の**有益候補**を見える化。有益候補を先生に促す仕組みは別 EPIC #1106）②**クラス検索**（参加コード完全一致・名前部分一致 / 詳細 / アーカイブ切替）③**期限切れ復元**（ddb-archive スナップショットを削除時期・先生でファセット絞り込み → dry-run → 実行。EPIC #1049 の CLI の UI 後継）
 3. **バグ報告**（S5 #1085 + 対応機能追加）: 既存バグ報告の一覧・状態フィルタ・詳細・添付 presigned DL に加え、**状態の変更と進捗コメント（開発者からの返信）**を既存 bug-report admin API の PATCH で行える（2 段階確認・終端ステータスは自動削除 TTL の警告つき。返信は報告者の「私の不具合報告」に表示され、非表示にしていた報告も再表示される — サーバー側の既存挙動）。詳細には**状態に応じた Claude 連携プロンプト**（`/bug-report` スキル向け・受付→Issue 化 / 改修 / 解決返信 / 再開）が表示され、ワンクリックでコピーして Claude Code に貼り付けられる
 
 ## 認証・認可モデル（要点）

infra/smalruby-admin/lambda/classroom-overview.ts

@@ -0,0 +1,186 @@
+/**
+ * Pure aggregation for the クラス・課題 俯瞰ダッシュボード (Admin, EPIC #1073).
+ *
+ * The operator wants to grasp "どんな課題がどれくらい作られているか" along three
+ * axes (chosen in the design interview): creation trend, content richness and
+ * theme tendency — NOT popularity/engagement. Kept pure so the whole shape is
+ * unit-tested without DynamoDB.
+ */
+
+/** A classroom row as stored (only the fields we aggregate on). */
+export interface ClassroomRow {
+  classroomId?: unknown;
+  className?: unknown;
+  assignmentName?: unknown;
+  teacherSub?: unknown;
+  status?: unknown; // 'active' | 'archived'
+  createdAt?: unknown;
+  content?: { pages?: { text?: string; imageKey?: string }[]; starterKey?: string };
+}
+
+/** Quota rows reuse the classrooms key space; never count them. */
+export function isRealClassroom(row: ClassroomRow): boolean {
+  return typeof row.classroomId === 'string' && !row.classroomId.includes('-quota#');
+}
+
+/**
+ * Content richness score (0-4): 1 for having any page, +1 for multiple pages,
+ * +1 for any page image, +1 for a starter project. Higher = more ready to
+ * share as-is to みんなの課題.
+ * @param row - classroom row
+ * @returns {score, pageCount, hasImages, hasStarter}
+ */
+export function richness(row: ClassroomRow): {
+  score: number; pageCount: number; hasImages: boolean; hasStarter: boolean;
+} {
+  const pages = row.content?.pages || [];
+  const pageCount = pages.length;
+  const hasImages = pages.some(p => typeof p?.imageKey === 'string' && p.imageKey.length > 0);
+  const hasStarter = typeof row.content?.starterKey === 'string' && row.content.starterKey.length > 0;
+  let score = 0;
+  if (pageCount >= 1) score += 1;
+  if (pageCount >= 2) score += 1;
+  if (hasImages) score += 1;
+  if (hasStarter) score += 1;
+  return { score, pageCount, hasImages, hasStarter };
+}
+
+/** Split a Japanese/English title into rough keyword tokens for tallying. */
+export function tokenizeTitle(title: string): string[] {
+  return title
+    .normalize('NFKC')
+    .toLowerCase()
+    // split on whitespace, punctuation and common separators (keep JP/EN/digits)
+    .split(/[\s、。・,.\/|:：;；\-—_（）()「」『』［］\[\]{}!！?？]+/u)
+    .map(t => t.trim())
+    .filter(t => t.length >= 2 && !/^\d+$/.test(t));
+}
+
+const MONTH_KEY = (iso: string): string => iso.slice(0, 7); // YYYY-MM
+
+/**
+ * Build the whole overview payload from every classroom row.
+ * @param rows - raw classroom items (quota rows are filtered out here)
+ * @param sharedTitles - normalized assignment titles already on みんなの課題
+ *   (to flag "likely already shared" candidates); pass [] if unknown
+ * @param nowMs - current time (injectable for deterministic tests)
+ * @returns the dashboard aggregation
+ */
+export function buildOverview(
+  rows: ClassroomRow[],
+  sharedTitles: string[],
+  nowMs: number,
+): {
+  summary: { total: number; active: number; archived: number; recent30d: number };
+  creationTrend: { month: string; count: number }[];
+  richnessDistribution: { score: number; count: number }[];
+  candidates: {
+    classroomId: string; className: string; assignmentName: string;
+    teacherSub: string; score: number; pageCount: number;
+    hasImages: boolean; hasStarter: boolean; createdAt: string; likelyShared: boolean;
+  }[];
+  themeKeywords: { keyword: string; count: number }[];
+} {
+  const classrooms = rows.filter(isRealClassroom);
+  const sharedSet = new Set(sharedTitles.map(t => t.normalize('NFKC').trim().toLowerCase()));
+  const cutoff30 = nowMs - 30 * 24 * 60 * 60 * 1000;
+
+  let active = 0;
+  let archived = 0;
+  let recent30d = 0;
+  const byMonth = new Map<string, number>();
+  const byScore = new Map<number, number>();
+  const keywordCount = new Map<string, number>();
+  const candidates: ReturnType<typeof buildOverview>['candidates'] = [];
+
+  for (const row of classrooms) {
+    const status = String(row.status || '');
+    if (status === 'archived') archived += 1; else active += 1;
+
+    const createdAt = typeof row.createdAt === 'string' ? row.createdAt : '';
+    if (createdAt) {
+      byMonth.set(MONTH_KEY(createdAt), (byMonth.get(MONTH_KEY(createdAt)) || 0) + 1);
+      if (Date.parse(createdAt) >= cutoff30) recent30d += 1;
+    }
+
+    const r = richness(row);
+    byScore.set(r.score, (byScore.get(r.score) || 0) + 1);
+
+    const assignmentName = typeof row.assignmentName === 'string' ? row.assignmentName : '';
+    const className = typeof row.className === 'string' ? row.className : '';
+    for (const token of [...tokenizeTitle(assignmentName), ...tokenizeTitle(className)]) {
+      keywordCount.set(token, (keywordCount.get(token) || 0) + 1);
+    }
+
+    // 有益候補: reasonably rich (>=3) content. Flag likely-already-shared so
+    // the operator focuses on the unshared ones.
+    if (r.score >= 3) {
+      const likelyShared = sharedSet.has(assignmentName.normalize('NFKC').trim().toLowerCase());
+      candidates.push({
+        classroomId: String(row.classroomId),
+        className,
+        assignmentName,
+        teacherSub: typeof row.teacherSub === 'string' ? row.teacherSub : '',
+        score: r.score,
+        pageCount: r.pageCount,
+        hasImages: r.hasImages,
+        hasStarter: r.hasStarter,
+        createdAt,
+        likelyShared,
+      });
+    }
+  }
+
+  const creationTrend = [...byMonth.entries()]
+    .map(([month, count]) => ({ month, count }))
+    .sort((a, b) => a.month.localeCompare(b.month));
+
+  const richnessDistribution = [0, 1, 2, 3, 4]
+    .map(score => ({ score, count: byScore.get(score) || 0 }));
+
+  // Unshared candidates first, then richer, then newer.
+  candidates.sort((a, b) =>
+    Number(a.likelyShared) - Number(b.likelyShared) ||
+    b.score - a.score ||
+    b.createdAt.localeCompare(a.createdAt));
+
+  const themeKeywords = [...keywordCount.entries()]
+    .map(([keyword, count]) => ({ keyword, count }))
+    .filter(k => k.count >= 2)
+    .sort((a, b) => b.count - a.count || a.keyword.localeCompare(b.keyword))
+    .slice(0, 30);
+
+  return {
+    summary: { total: classrooms.length, active, archived, recent30d },
+    creationTrend,
+    richnessDistribution,
+    candidates: candidates.slice(0, 50),
+    themeKeywords,
+  };
+}
+
+/**
+ * Facet buckets for the restore tab (削除済みスナップショット). Groups a large
+ * candidate list by deletion month and by teacher so the operator can narrow
+ * down like the みんなの課題 catalog.
+ * @param snapshots - matched snapshot summaries
+ * @returns facet counts
+ */
+export function buildRestoreFacets(
+  snapshots: { deletedAt?: string | null; teacherSub?: string }[],
+): { byMonth: { month: string; count: number }[]; byTeacher: { teacherSub: string; count: number }[] } {
+  const byMonth = new Map<string, number>();
+  const byTeacher = new Map<string, number>();
+  for (const s of snapshots) {
+    const month = s.deletedAt ? s.deletedAt.slice(0, 7) : '(不明)';
+    byMonth.set(month, (byMonth.get(month) || 0) + 1);
+    const t = s.teacherSub || '(不明)';
+    byTeacher.set(t, (byTeacher.get(t) || 0) + 1);
+  }
+  return {
+    byMonth: [...byMonth.entries()].map(([month, count]) => ({ month, count }))
+      .sort((a, b) => b.month.localeCompare(a.month)),
+    byTeacher: [...byTeacher.entries()].map(([teacherSub, count]) => ({ teacherSub, count }))
+      .sort((a, b) => b.count - a.count),
+  };
+}

infra/smalruby-admin/lambda/handler.ts

@@ -30,6 +30,7 @@ import { OAuth2Client } from 'google-auth-library';
 import {
   buildRestorePlan, matchSnapshot, PlannedItem, RestorePlanInput, Snapshot,
 } from './restore-plan';
+import { buildOverview, buildRestoreFacets, ClassroomRow } from './classroom-overview';
 
 // --- Configuration ---
 
@@ -416,6 +417,22 @@ async function handleListClassrooms(
   return { statusCode: 200, body: JSON.stringify({ items: items.slice(0, 100) }) };
 }
 
+async function handleClassroomOverview(
+  identity: AdminIdentity,
+): Promise<APIGatewayProxyStructuredResultV2> {
+  audit('classroom.overview', identity, {});
+  const [classroomRows, sharedRows] = await Promise.all([
+    scanAll(CLASSROOMS_TABLE),
+    // Titles already on みんなの課題 — flag likely-shared candidates.
+    scanAll(SHARED_ASSIGNMENTS_TABLE).catch(() => [] as Record<string, unknown>[]),
+  ]);
+  const sharedTitles = sharedRows
+    .map(r => (typeof r.title === 'string' ? r.title : ''))
+    .filter(Boolean);
+  const overview = buildOverview(classroomRows as ClassroomRow[], sharedTitles, Date.now());
+  return { statusCode: 200, body: JSON.stringify(overview) };
+}
+
 async function handleGetClassroom(
   identity: AdminIdentity, classroomId: string,
 ): Promise<APIGatewayProxyStructuredResultV2> {
@@ -522,24 +539,45 @@ async function collectSnapshotChildren(kind: string, classroomId: string): Promi
 async function handleSearchRestoreCandidates(
   identity: AdminIdentity, query: Record<string, string | undefined>,
 ): Promise<APIGatewayProxyStructuredResultV2> {
+  // q is now optional: the operator can browse ALL deleted snapshots and
+  // narrow with facets (削除時期 / 先生) instead of only text search, because
+  // the raw list is too large to eyeball (みんなの課題 catalog style).
   const q = (query.q || '').trim();
-  if (!q) {
-    throw new ValidationError('q is required');
-  }
-  audit('classroom.searchSnapshots', identity, { q });
+  const monthFilter = (query.month || '').trim();
+  const teacherFilter = (query.teacher || '').trim();
+  audit('classroom.searchSnapshots', identity, { q: q || null, month: monthFilter || null });
 
   const keys = await listArchiveKeys(`${ARCHIVE_PREFIX}/classrooms/`);
-  const matches: Record<string, unknown>[] = [];
+  const all: { item: Record<string, unknown>; deletedAt: string | null; teacherSub: string }[] = [];
   for (const key of keys) {
     const snapshot = await readSnapshot(key);
-    if (snapshot && matchSnapshot(snapshot, q)) {
-      matches.push({
-        ...mapClassroomForAdmin(snapshot.item),
+    if (snapshot?.item) {
+      all.push({
+        item: snapshot.item,
         deletedAt: snapshot.deletedAt,
+        teacherSub: typeof snapshot.item.teacherSub === 'string' ? snapshot.item.teacherSub : '',
       });
     }
   }
-  return { statusCode: 200, body: JSON.stringify({ items: matches }) };
+
+  // Facets are computed over everything (so the operator sees the full shape),
+  // the item list is what survives the active filters.
+  const facets = buildRestoreFacets(all);
+  const matches = all
+    .filter(s => !q || matchSnapshot({ table: 'classrooms', deletedAt: s.deletedAt, eventId: null, item: s.item }, q))
+    .filter(s => !monthFilter || (s.deletedAt || '').slice(0, 7) === monthFilter)
+    .filter(s => !teacherFilter || s.teacherSub === teacherFilter)
+    .map(s => ({
+      ...mapClassroomForAdmin(s.item),
+      teacherSub: s.teacherSub,
+      deletedAt: s.deletedAt,
+    }))
+    .sort((a, b) => String(b.deletedAt || '').localeCompare(String(a.deletedAt || '')));
+
+  return {
+    statusCode: 200,
+    body: JSON.stringify({ items: matches.slice(0, 200), total: matches.length, facets }),
+  };
 }
 
 async function gatherRestoreInput(classroomId: string): Promise<{
@@ -711,6 +749,9 @@ export const handler = async (event: APIGatewayProxyEventV2): Promise<APIGateway
       const sharedId = event.pathParameters?.sharedId || '';
       result = await handleSetSharedStatus(identity, sharedId, body);
 
+    } else if (method === 'GET' && path === '/admin/classrooms/overview') {
+      result = await handleClassroomOverview(identity);
+
     } else if (method === 'GET' && path === '/admin/classrooms') {
       result = await handleListClassrooms(identity, event.queryStringParameters || {});
 

infra/smalruby-admin/lambda/tests/classroom-overview.test.ts

@@ -0,0 +1,99 @@
+import {
+  buildOverview, buildRestoreFacets, isRealClassroom, richness, tokenizeTitle,
+} from '../classroom-overview';
+
+const NOW = Date.parse('2026-07-19T00:00:00.000Z');
+
+const rows = [
+  // rich + recent + unshared → top candidate
+  {
+    classroomId: 'c1', className: '5年1組', assignmentName: 'ねこ迷路ゲーム', teacherSub: 't1',
+    status: 'active', createdAt: '2026-07-10T00:00:00.000Z',
+    content: { pages: [{ text: 'a', imageKey: 'k1' }, { text: 'b' }], starterKey: 's1' },
+  },
+  // rich but already shared
+  {
+    classroomId: 'c2', className: '6年2組', assignmentName: 'ねこあつめ入門', teacherSub: 't2',
+    status: 'archived', createdAt: '2026-06-05T00:00:00.000Z',
+    content: { pages: [{ text: 'a', imageKey: 'k' }, { text: 'b' }], starterKey: 's' },
+  },
+  // thin content → not a candidate
+  {
+    classroomId: 'c3', className: '5年1組', assignmentName: 'ねこ体操', teacherSub: 't1',
+    status: 'active', createdAt: '2026-07-01T00:00:00.000Z',
+    content: { pages: [{ text: 'a' }] },
+  },
+  // quota row → excluded from everything
+  { classroomId: 'eval-quota#t1#2026-07-19', status: 'active', createdAt: '2026-07-19T00:00:00.000Z' },
+];
+
+describe('richness / tokenizeTitle / isRealClassroom', () => {
+  test('richness scores pages, images and starter', () => {
+    expect(richness(rows[0]).score).toBe(4); // >=2 pages(2) + image(1) + starter(1)
+    expect(richness(rows[2]).score).toBe(1); // 1 page only
+    expect(richness({}).score).toBe(0);
+  });
+
+  test('tokenizeTitle drops short tokens and pure numbers', () => {
+    const t = tokenizeTitle('ねこ迷路ゲーム 2026');
+    expect(t).toContain('ねこ迷路ゲーム');
+    expect(t).not.toContain('2026');
+  });
+
+  test('quota rows are not real classrooms', () => {
+    expect(isRealClassroom(rows[3])).toBe(false);
+    expect(isRealClassroom(rows[0])).toBe(true);
+  });
+});
+
+describe('buildOverview (issue #1106 dashboard)', () => {
+  const o = buildOverview(rows, ['ねこあつめ入門'], NOW);
+
+  test('summary counts exclude quota rows and split active/archived', () => {
+    expect(o.summary.total).toBe(3);
+    expect(o.summary.active).toBe(2);
+    expect(o.summary.archived).toBe(1);
+    expect(o.summary.recent30d).toBe(2); // c1 and c3 within 30d of NOW
+  });
+
+  test('creation trend is per-month, ascending', () => {
+    expect(o.creationTrend).toEqual([
+      { month: '2026-06', count: 1 },
+      { month: '2026-07', count: 2 },
+    ]);
+  });
+
+  test('richness distribution covers scores 0-4', () => {
+    expect(o.richnessDistribution).toHaveLength(5);
+    expect(o.richnessDistribution.find(d => d.score === 4)?.count).toBe(2);
+  });
+
+  test('candidates: unshared rich ones first, shared flagged, thin excluded', () => {
+    expect(o.candidates.map(c => c.classroomId)).toEqual(['c1', 'c2']);
+    expect(o.candidates[0].likelyShared).toBe(false);
+    expect(o.candidates[1].likelyShared).toBe(true); // ねこあつめ入門 already shared
+    expect(o.candidates.some(c => c.classroomId === 'c3')).toBe(false);
+  });
+
+  test('theme keywords tally repeated tokens only', () => {
+    // '5年1組' appears on c1 and c3
+    expect(o.themeKeywords.some(k => k.keyword === '5年1組' && k.count === 2)).toBe(true);
+  });
+});
+
+describe('buildRestoreFacets (issue #1084 restore facets)', () => {
+  test('groups snapshots by deletion month and teacher', () => {
+    const f = buildRestoreFacets([
+      { deletedAt: '2026-07-10T00:00:00Z', teacherSub: 't1' },
+      { deletedAt: '2026-07-11T00:00:00Z', teacherSub: 't1' },
+      { deletedAt: '2026-06-01T00:00:00Z', teacherSub: 't2' },
+      { deletedAt: null, teacherSub: '' },
+    ]);
+    expect(f.byMonth).toEqual([
+      { month: '2026-07', count: 2 },
+      { month: '2026-06', count: 1 },
+      { month: '(不明)', count: 1 },
+    ]);
+    expect(f.byTeacher[0]).toEqual({ teacherSub: 't1', count: 2 });
+  });
+});