refactor(delete): make undo unconditional, remove undo toggle and button delay

- Remove delete_undo_enabled setting (backend default, frontend state,
  settings modal UI, 10 locales); staged deletes with 30s undo are now
  the only delete path and stale settings keys are silently ignored
- Remove the 1500ms delete-button arm delay (armDeleteButton) from all
  delete modals; misclicks are recoverable via the undo toast
- Delete modal always shows the recoverable warning
- Log the first staged file path in staging log lines for easier support

locales/zh-TW.json

@@ -443,7 +443,6 @@
             "label": "跳過已下載的模型版本",
             "help": "啟用後，如果下載歷史服務記錄顯示該版本已下載，LoRA Manager 將跳過下載該模型版本。適用於所有下載流程。"
         },
-        "deleteUndoEnabled": "[TODO: Translate] Keep deleted items recoverable for 30 seconds (undo)",
         "layoutSettings": {
             "groupByModel": "按模型分組",
             "groupByModelHelp": "啟用後，每個 Civitai 模型僅顯示最新版本的單張卡片，舊版本將被隱藏。",
@@ -1281,7 +1280,6 @@
             "freesSpace": "[TODO: Translate] Frees {size}",
             "title": "刪除模型",
             "message": "您確定要刪除此模型及所有相關檔案嗎？",
-            "permanentWarning": "[TODO: Translate] This will permanently delete the file from disk.",
             "recoverableWarning": "[TODO: Translate] This will permanently delete the file after 30 seconds unless you undo."
         },
         "excludeModel": {