AI: address review on PR #478

Refs #454

## Automated implementation (requires human review)
[SidebarComponent.tsx](frontend/src/components/layout/SidebarComponent.tsx) の1行を修正しました。`overflow-y-auto` を `md` 以上に限定し、スマホでサゼストがサイドバーの領域外で切られる原因を取り除きました。

差分を確認済みです。指定に従い、テスト・lint・ビルドは未実行です。実画面でのスマホ表示とPC表示の確認も未実施です。

## Automated review (not a guarantee of correctness)
```text
The change restricts sidebar scrolling to medium and larger viewports. No actionable regression was identified in the current diff.

```

## Verification
- Tests/builds/migrations were not authorized and were not invoked by the controller.
- Codex was instructed not to run them; its command transcript should be inspected.
- Do not merge before manual acceptance and required checks.

---------

Co-authored-by: Codex Night Worker <codex-night@localhost>
Reviewed-on: #456
Co-authored-by: テツノニジカ <969+codex-bot@noreply.localhost>

frontend/src/components/PostEditForm.tsx

@@ -153,6 +153,21 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
     setDisabled (true)
     try
     {
+      const titleMissing = !title?.trim ()
+      const thumbnailMissing =
+	  !titleMissing
+	  && !(post.thumbnail?.trim () || post.thumbnailBase?.trim ())
+
+      if ((titleMissing || thumbnailMissing)
+	  && !(await dialogue.confirm ({
+	      title: titleMissing
+		  ? label ('edit.titleMissingConfirmation')
+		  : label ('edit.thumbnailMissingConfirmation'),
+	      confirmText: label ('shared:actions.update'),
+	      cancelText: label ('shared:actions.cancel'),
+	      closeLabel: label ('settings:actions.close') })))
+	return
+
       await update ({ id: post.id, title, tags, parentPostIds,
 		      duration: videoFlg ? duration : null,
 		      originalCreatedFrom, originalCreatedBefore },

frontend/src/components/layout/SidebarComponent.test.tsx

@@ -70,6 +70,16 @@ describe ('SidebarComponent', () => {
     vi.spyOn (HTMLElement.prototype, 'hasPointerCapture').mockReturnValue (true)
   })
 
+  it ('limits sidebar scrolling to desktop to avoid clipping mobile suggestions', () => {
+    renderSidebar ()
+
+    // jsdom has no layout; guard the responsive classes responsible for clipping.
+    const sidebar = screen.getByText ('Sidebar body')
+
+    expect (sidebar).not.toHaveClass ('overflow-y-auto')
+    expect (sidebar).toHaveClass ('md:overflow-y-auto')
+  })
+
   it ('uses maxWidth without applying the container main-width reserve twice', async () => {
     localStorage.setItem ('sidebar:test-sidebar:left:width', '700')
     const onWidthChange = vi.fn ()

frontend/src/components/layout/SidebarComponent.tsx

@@ -339,7 +339,7 @@ const SidebarComponent: FC<Props> = ({
 	  </style>
 	</Helmet>
 
-	<div className="h-full overflow-y-auto p-4 sidebar">
+	<div className="h-full md:overflow-y-auto p-4 sidebar">
 	  {children}
 	</div>
 

frontend/src/locales/ain-Kana/posts.json

@@ -1,4 +1,5 @@
 {
+  "_untranslated": ["edit.titleMissingConfirmation", "edit.thumbnailMissingConfirmation"],
   "list": {
     "tagline": "{{brand}}",
     "empty": "ミンタㇻ　タ　ネン　カ　イサㇺ",
@@ -31,6 +32,8 @@
     "showExternal": "ソイタㇰ　ソㇱ　アヌカレ"
   },
   "edit": {
+    "titleMissingConfirmation": "タイトルが設定されてゐません．更新しますか?",
+    "thumbnailMissingConfirmation": "サムネールが設定されてゐません．更新しますか?",
     "validationFailed": "アシㇼ　カㇻ　カ　エアイカㇷ゚……",
     "conflictTitle": "モㇱマ　クㇽ　アシㇼ　カㇻ　ワ　アン！",
     "conflictDescription": "モㇱマ　イカㇻ　クㇽ　エエトコ　アシㇼ　カㇻ　ワ　アン。",

frontend/src/locales/ja/posts.json

@@ -22,6 +22,8 @@
     "question": "表示しますか?", "showExternal": "外部ページを表示"
   },
   "edit": {
+    "titleMissingConfirmation": "タイトルが設定されてゐません．更新しますか?",
+    "thumbnailMissingConfirmation": "サムネールが設定されてゐません．更新しますか?",
     "validationFailed": "更新はできなかったよ……",
     "conflictTitle": "競合が発生しました．",
     "conflictDescription": "ほかの耕作員が先に更新してゐます．",

frontend/src/pages/tags/TagDetailPage.test.tsx

@@ -35,6 +35,10 @@ const renderPage = () =>
 describe ('TagDetailPage', () => {
   beforeEach (() => {
     vi.clearAllMocks ()
+    tagsApi.fetchTag.mockReset ()
+    api.apiPut.mockReset ()
+    api.isApiError.mockReset ()
+    toastApi.toast.mockReset ()
     api.isApiError.mockReturnValue (false)
   })
 
@@ -51,8 +55,11 @@ describe ('TagDetailPage', () => {
   })
 
   it ('submits edited tag fields', async () => {
-    tagsApi.fetchTag.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
-    api.apiPut.mockResolvedValueOnce (buildTag ({ id: 7, name: 'new', aliases: ['alias'] }))
+    const updatedTag = buildTag ({ id: 7, name: 'new', aliases: ['alias'] })
+    tagsApi.fetchTag
+	.mockResolvedValue (updatedTag)
+	.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
+    api.apiPut.mockResolvedValueOnce (updatedTag)
 
     renderPage ()