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

@@ -1,5 +1,5 @@
-# Tool_OCR - Environment Configuration Template
-# Copy this file to .env and fill in your actual values
+# Tool_OCR - Docker Environment Configuration
+# Copy this file to .env when deploying with Docker
 
 # ===== Database Configuration =====
 MYSQL_HOST=mysql.theaken.com
@@ -9,18 +9,17 @@ MYSQL_PASSWORD=WLeSCi0yhtc7
 MYSQL_DATABASE=db_A060
 
 # ===== Application Configuration =====
-# Server ports
-BACKEND_PORT=12010
-FRONTEND_PORT=12011
+# External port (exposed to host)
+FRONTEND_PORT=12010
 
-# Security
+# 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
-PADDLEOCR_MODEL_DIR=./models/paddleocr
+# 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
@@ -33,24 +32,24 @@ MAX_OCR_WORKERS=4
 MAX_UPLOAD_SIZE=52428800
 # Allowed file extensions (comma-separated)
 ALLOWED_EXTENSIONS=png,jpg,jpeg,pdf,bmp,tiff,doc,docx,ppt,pptx
-# Upload directories
-UPLOAD_DIR=./uploads
-TEMP_DIR=./uploads/temp
-PROCESSED_DIR=./uploads/processed
-IMAGES_DIR=./uploads/images
+# 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
-STORAGE_DIR=./storage
-MARKDOWN_DIR=./storage/markdown
-JSON_DIR=./storage/json
-EXPORTS_DIR=./storage/exports
+# 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 (auto-detected if installed via brew)
-PANDOC_PATH=/opt/homebrew/bin/pandoc
-# WeasyPrint font directory
-FONT_DIR=/System/Library/Fonts
+# 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)
@@ -64,8 +63,8 @@ PDF_MARGIN_RIGHT=20
 ENABLE_TRANSLATION=false
 # Translation engine: offline (argostranslate) or api (future)
 TRANSLATION_ENGINE=offline
-# Argostranslate models directory
-ARGOSTRANSLATE_MODELS_DIR=./models/argostranslate
+# Argostranslate models directory (inside container)
+ARGOSTRANSLATE_MODELS_DIR=/app/backend/models/argostranslate
 
 # ===== Background Tasks Configuration =====
 # Task queue type: memory (default) or redis (future)
@@ -75,8 +74,9 @@ TASK_QUEUE_TYPE=memory
 
 # ===== CORS Configuration =====
 # Allowed origins (comma-separated, * for all)
-CORS_ORIGINS=http://localhost:12011,http://127.0.0.1:12011
+# For Docker, use the external URL
+CORS_ORIGINS=http://localhost:12010,http://127.0.0.1:12010
 
 # ===== Logging Configuration =====
 LOG_LEVEL=INFO
-LOG_FILE=./logs/app.log
+LOG_FILE=/app/backend/logs/app.log