chore: 初始版本提交 - 简化架构 + 轮询改造

- 移除 Motia Streams 实时通信，改用 3 秒轮询
- 简化前端代码，移除冗余组件
- 简化后端架构，准备 FastAPI 重构
- 更新 pixi.toml 环境配置
- 保留 bttoxin_digger_v5_repro 作为参考文档

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

docker/nginx/default.conf

@@ -0,0 +1,33 @@
+server {
+    listen 80;
+    server_name _;
+    root /var/www/html;
+    index index.html;
+
+    # Gzip 压缩
+    gzip on;
+    gzip_types text/plain text/css application/json application/javascript text/xml application/xml;
+
+    # 允许上传最大 100M
+    client_max_body_size 100M;
+
+    # 前端路由 (SPA)
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # API 代理到后端
+    location /api/ {
+        proxy_pass http://127.0.0.1:8000/api/;
+        proxy_http_version 1.1;
+        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;
+    }
+
+    # 健康检查
+    location /health {
+        proxy_pass http://127.0.0.1:8000/api/health;
+    }
+}