feat: upgrade PP-StructureV3 models to latest versions

- Layout: PP-DocLayout-S → PP-DocLayout_plus-L (83.2% mAP)
- Table: Single model → Dual SLANeXt (wired/wireless)
- Formula: PP-FormulaNet_plus-L for enhanced recognition
- Add preprocessing flags support (orientation, unwarping)
- Update frontend i18n descriptions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/i18n/locales/zh-TW.json

@@ -56,11 +56,11 @@
     "layoutModel": {
       "title": "版面偵測模型",
       "chinese": "中文文件模型",
-      "chineseDesc": "PP-DocLayout-S - 適用於中文表單、合約、發票（推薦）",
+      "chineseDesc": "PP-DocLayout_plus-L (83.2% mAP) - 適用於複雜中文文件，支援20種版面元素（推薦）",
       "default": "標準模型",
-      "defaultDesc": "PubLayNet 模型 - 適用於英文學術論文、報告",
+      "defaultDesc": "PubLayNet 模型 (~94% mAP) - 適用於英文學術論文、報告",
       "cdla": "CDLA 模型",
-      "cdlaDesc": "專用中文版面分析模型 - 適用於複雜中文版面",
+      "cdlaDesc": "CDLA 版面分析模型 (~86% mAP) - 專用中文版面分析",
       "recommended": "推薦",
       "note": "版面模型會影響文件結構（表格、文字區塊、圖片）的偵測效果。請根據您的文件類型選擇適合的模型。"
     }