feat: Docker化部署 - 單容器架構轉換

將 Tool_OCR 從 macOS conda 環境轉換為 Docker 單容器部署方案。
前後端整合於同一容器，通過 Nginx 反向代理，僅對外暴露單一端口。

## 新增功能
- Docker 單容器架構（Frontend + Backend + Nginx）
- 多階段構建優化鏡像大小
- Supervisor 進程管理
- 健康檢查機制
- 完整部署文檔

## 技術細節
- 對外端口：12015（原 12010 已被佔用）
- 內部架構：Nginx(12015) → FastAPI(8000)
- 前端靜態文件由 Nginx 直接服務
- API 請求通過 Nginx 反向代理

## 系統依賴完善
- libmagic1：文件類型檢測
- LibreOffice：Office 文檔轉換
- paddlex[ocr]：PP-StructureV3 版面分析
- 中日韓字體支援

## 配置調整
- 環境變數路徑：macOS 路徑 → 容器絕對路徑
- 前端 API URL：修正為統一端口 12015
- Pip 安裝：延長超時至 600 秒，重試 5 次
- CRLF 轉換：自動處理 Windows 換行符

## 清理
- 移除臨時文檔（API_FIX_SUMMARY.md 等 7 個文檔）

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

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

.env.docker

@@ -0,0 +1,82 @@
+# Tool_OCR - Docker Environment Configuration
+# Copy this file to .env when deploying with Docker
+
+# ===== Database Configuration =====
+MYSQL_HOST=mysql.theaken.com
+MYSQL_PORT=33306
+MYSQL_USER=A060
+MYSQL_PASSWORD=WLeSCi0yhtc7
+MYSQL_DATABASE=db_A060
+
+# ===== Application Configuration =====
+# External port (exposed to host)
+FRONTEND_PORT=12015
+
+# Security (IMPORTANT: Change SECRET_KEY in production!)
+SECRET_KEY=your-secret-key-here-please-change-this-to-random-string
+ALGORITHM=HS256
+ACCESS_TOKEN_EXPIRE_MINUTES=1440
+
+# ===== OCR Configuration =====
+# PaddleOCR model directory (inside container)
+PADDLEOCR_MODEL_DIR=/app/backend/models/paddleocr
+# Supported languages (comma-separated)
+OCR_LANGUAGES=ch,en,japan,korean
+# Default confidence threshold
+OCR_CONFIDENCE_THRESHOLD=0.5
+# Maximum concurrent OCR workers
+MAX_OCR_WORKERS=4
+
+# ===== File Upload Configuration =====
+# Maximum file size in bytes (50MB default)
+MAX_UPLOAD_SIZE=52428800
+# Allowed file extensions (comma-separated)
+ALLOWED_EXTENSIONS=png,jpg,jpeg,pdf,bmp,tiff,doc,docx,ppt,pptx
+# Upload directories (inside container)
+UPLOAD_DIR=/app/backend/uploads
+TEMP_DIR=/app/backend/uploads/temp
+PROCESSED_DIR=/app/backend/uploads/processed
+IMAGES_DIR=/app/backend/uploads/images
+
+# ===== Export Configuration =====
+# Storage directories (inside container)
+STORAGE_DIR=/app/backend/storage
+MARKDOWN_DIR=/app/backend/storage/markdown
+JSON_DIR=/app/backend/storage/json
+EXPORTS_DIR=/app/backend/storage/exports
+
+# ===== PDF Generation Configuration =====
+# Pandoc path (inside container)
+PANDOC_PATH=/usr/bin/pandoc
+# Font directory (inside container)
+FONT_DIR=/usr/share/fonts
+# Default PDF page size
+PDF_PAGE_SIZE=A4
+# Default PDF margins (mm)
+PDF_MARGIN_TOP=20
+PDF_MARGIN_BOTTOM=20
+PDF_MARGIN_LEFT=20
+PDF_MARGIN_RIGHT=20
+
+# ===== Translation Configuration (Reserved) =====
+# Enable translation feature (reserved for future)
+ENABLE_TRANSLATION=false
+# Translation engine: offline (argostranslate) or api (future)
+TRANSLATION_ENGINE=offline
+# Argostranslate models directory (inside container)
+ARGOSTRANSLATE_MODELS_DIR=/app/backend/models/argostranslate
+
+# ===== Background Tasks Configuration =====
+# Task queue type: memory (default) or redis (future)
+TASK_QUEUE_TYPE=memory
+# Redis URL (if using redis)
+# REDIS_URL=redis://localhost:6379/0
+
+# ===== CORS Configuration =====
+# Allowed origins (comma-separated, * for all)
+# For Docker, use the external URL
+CORS_ORIGINS=http://localhost:12015,http://127.0.0.1:12015
+
+# ===== Logging Configuration =====
+LOG_LEVEL=INFO
+LOG_FILE=/app/backend/logs/app.log