i18n: translate model-source strings into 9 locales

Complete the 15 [TODO: Translate] keys the model-source feature left behind
(modelCard.actions.viewOnSource, loras.contextMenu.linkModelSource,
modals.linkModelSource.*, modals.model.versions.sourceGroupInfo,
toast.contextMenu.enrichNeedsSource, toast.contextMenu.enrichUnsupportedSource),
and refresh the two enrichment labels that feature made stale.

- Brands stay Latin per R3: Hugging Face / ModelScope / TensorArt appear
  verbatim, and {source} is substituted by the caller at runtime, so no locale
  embeds a transliterated platform name. The placeholder-URL value
  (modals.linkModelSource.urlPlaceholder) stays byte-identical to en.json per
  the §6 URL exception.
- "model source" / "model page" / "model card" are new nouns and each locale
  gets exactly one rendering; "AI enrichment" reuses the noun already in each
  file from the previous enrichHfAgent copy. All of it is recorded in §2.
- modelCard.actions.viewOnSource follows each locale's existing
  viewOnHuggingFace pattern rather than the neighbouring viewOnCivitai one, so
  de/ru/he/ja/ko do not gain a third "View on ..." shape.
- loras.contextMenu.enrichHfAgent and loras.bulkOperations.enrichHfAgent read
  "AI HF metadata" in all nine locales. The feature invalidated that by also
  covering ModelScope, so both values drop the HF qualifier (the key names keep
  the historical Hf, and the guidelines now say so).
- Script conventions: fr keeps ASCII apostrophes and a space before ':' (the
  file is 351 ASCII vs 26 U+2019 and the modal being replaced was ASCII); ko
  keeps ASCII ':' and '()' (188 vs 6); CJK locales keep full-width punctuation;
  every ellipsis is ASCII '...'. Placeholders are verbatim per R2.
- modals.linkModelSource.enrichNote is phrased as a rule with the current
  exception in parentheses, so the guidelines call that out for whoever adds
  the next link-only source.

pytest tests/i18n: 20 passed, and scripts/sync_translation_keys.py --dry-run is
a no-op (no missing and no stale keys). Frontend: 1130 JS + 91 Vue passed.
Backend: 2815 passed. en.json is untouched by this commit.

locales/ja.json

@@ -139,7 +139,7 @@
             "viewOnCivitai": "CivitAIで表示",
             "notAvailableFromCivitai": "CivitAIでは利用できません",
             "viewOnHuggingFace": "Hugging Face で見る",
-            "viewOnSource": "[TODO: Translate] View on {source}",
+            "viewOnSource": "{source} で見る",
             "sendToWorkflow": "ComfyUIに送信（クリック：追加、Shift+クリック：置換）",
             "copyLoRASyntax": "LoRA構文をコピー",
             "checkpointNameCopied": "Checkpointの名前をコピーしました",
@@ -868,14 +868,14 @@
                 "complete": "自動整理が完了しました",
                 "error": "エラー：{error}"
             },
-            "enrichHfAgent": "HF メタデータをAIで補完"
+            "enrichHfAgent": "メタデータをAIで補完"
         },
         "contextMenu": {
             "refreshMetadata": "CivitAIデータを更新",
             "checkUpdates": "更新確認",
             "linkModel": "モデルをリンク",
             "linkCivitai": "CivitAI にリンク",
-            "linkModelSource": "[TODO: Translate] Link to Model Source",
+            "linkModelSource": "モデルソースにリンク",
             "copySyntax": "LoRA構文をコピー",
             "copyFilename": "モデルファイル名をコピー",
             "copyRecipeSyntax": "レシピ構文をコピー",
@@ -897,7 +897,7 @@
             "viewAllLoras": "すべてのLoRAを表示",
             "downloadMissingLoras": "不足しているLoRAをダウンロード",
             "deleteRecipe": "レシピを削除",
-            "enrichHfAgent": "HF メタデータをAIで補完"
+            "enrichHfAgent": "メタデータをAIで補完"
         }
     },
     "recipes": {
@@ -1598,16 +1598,16 @@
             "root": "ルート"
         },
         "linkModelSource": {
-            "title": "[TODO: Translate] Link to Model Source",
-            "infoText": "[TODO: Translate] Paste the model page URL to associate this model with its source. Linking enables AI-powered metadata enrichment for Hugging Face and ModelScope models.",
-            "urlLabel": "[TODO: Translate] Model Page URL:",
-            "urlPlaceholder": "[TODO: Translate] https://huggingface.co/user/repo",
-            "helpText": "[TODO: Translate] Enter the full URL of the model page. Supported sites:",
-            "enrichNote": "[TODO: Translate] Note: AI metadata enrichment requires an accessible model card. TensorArt pages are not readable by the backend, so only the link is stored.",
-            "urlRequired": "[TODO: Translate] Please enter a model page URL.",
-            "invalidUrl": "[TODO: Translate] Unsupported URL. Supported sites: Hugging Face, ModelScope, TensorArt.",
-            "linking": "[TODO: Translate] Linking model source...",
-            "confirmAction": "[TODO: Translate] Save & Link"
+            "title": "モデルソースにリンク",
+            "infoText": "モデルページの URL を貼り付けて、このモデルをソースに関連付けます。リンクすると、Hugging Face と ModelScope のモデルで AI によるメタデータ補完が有効になります。",
+            "urlLabel": "モデルページ URL：",
+            "urlPlaceholder": "https://huggingface.co/user/repo",
+            "helpText": "完全なモデルページ URL を入力してください。対応サイト：",
+            "enrichNote": "AI 補完には読み取り可能なモデルカードが必要です。モデルカードを公開していないサイト（現在は TensorArt）はリンクのみ可能です。",
+            "urlRequired": "モデルページの URL を入力してください。",
+            "invalidUrl": "サポートされていない URL です。対応サイト：Hugging Face、ModelScope、TensorArt。",
+            "linking": "モデルソースをリンクしています...",
+            "confirmAction": "保存＆リンク"
         },
         "relinkCivitai": {
             "title": "CivitAIに再リンク",
@@ -1852,7 +1852,7 @@
                 "empty": "このモデルにはまだバージョン履歴がありません。",
                 "error": "バージョンの読み込みに失敗しました。",
                 "missingModelId": "このモデルにはCivitAIのモデルIDがありません。",
-                "sourceGroupInfo": "[TODO: Translate] This is a {source} model group. Open the library to see all versions in the grid.",
+                "sourceGroupInfo": "これは {source} モデルグループです。ライブラリを開いてグリッドですべてのバージョンを表示してください。",
                 "confirm": {
                     "delete": "このバージョンをライブラリから削除しますか？"
                 },
@@ -2489,8 +2489,8 @@
             "fetchMetadataFirst": "最初にCivitAIからメタデータを取得してください",
             "noCivitaiInfo": "CivitAI情報が利用できません",
             "missingHash": "モデルハッシュが利用できません",
-            "enrichNeedsSource": "[TODO: Translate] Link this model to a model source first (Link Model → Link to Model Source)",
-            "enrichUnsupportedSource": "[TODO: Translate] AI enrichment is not available for {source} models"
+            "enrichNeedsSource": "まずこのモデルをモデルソースにリンクしてください（モデルをリンク → モデルソースにリンク）",
+            "enrichUnsupportedSource": "{source} モデルでは AI 補完を利用できません"
         },
         "exampleImages": {
             "pathUpdated": "例画像パスが正常に更新されました",