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>

docker/default.conf

@@ -0,0 +1,89 @@
+# Nginx Site Configuration for Tool_OCR
+
+upstream backend {
+    server 127.0.0.1:8000;
+    keepalive 32;
+}
+
+server {
+    listen 12015;
+    server_name _;
+
+    # Security headers
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-XSS-Protection "1; mode=block" always;
+
+    # Root directory for frontend
+    root /app/frontend/dist;
+    index index.html;
+
+    # Logging
+    access_log /var/log/nginx/tool_ocr_access.log;
+    error_log /var/log/nginx/tool_ocr_error.log;
+
+    # Backend API proxy
+    location /api/ {
+        proxy_pass http://backend/api/;
+        proxy_http_version 1.1;
+
+        # Headers
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header Connection "";
+
+        # Timeouts
+        proxy_connect_timeout 60s;
+        proxy_send_timeout 300s;
+        proxy_read_timeout 300s;
+
+        # Buffering
+        proxy_buffering off;
+        proxy_request_buffering off;
+    }
+
+    # Health check endpoint (backend)
+    location /health {
+        proxy_pass http://backend/health;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header Connection "";
+    }
+
+    # API docs (backend)
+    location /docs {
+        proxy_pass http://backend/docs;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header Connection "";
+    }
+
+    location /openapi.json {
+        proxy_pass http://backend/openapi.json;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header Connection "";
+    }
+
+    # Frontend static files with caching
+    location /assets/ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    # Frontend - React Router support (SPA fallback)
+    location / {
+        try_files $uri $uri/ /index.html;
+        expires -1;
+        add_header Cache-Control "no-store, no-cache, must-revalidate";
+    }
+
+    # Deny access to hidden files
+    location ~ /\. {
+        deny all;
+        access_log off;
+        log_not_found off;
+    }
+}