feat: 移除 Docker 部署，添加 Gitea CI/CD workflows

- 删除 docker-compose.yml、Dockerfile、.dockerignore、docker/ 目录
- 更新 deploy.sh：移除 Docker Compose MySQL 启动，改为 systemd 检查
- 新增 .gitea/workflows/deploy.yml：手动触发、rsync + SSH + PM2 部署
- 新增 .gitea/workflows/ci.yml：PR lint + typecheck + test 自动检查

apps/admin/Dockerfile

@@ -1,14 +0,0 @@
-FROM node:22-alpine AS builder
-WORKDIR /app
-COPY package*.json ./
-COPY apps/admin/package.json ./apps/admin/package.json
-COPY packages/typescript-config/package.json ./packages/typescript-config/package.json
-RUN npm ci
-COPY . .
-RUN npm run build -w @gongxue/admin
-
-FROM nginx:alpine
-COPY --from=builder /app/apps/admin/dist /usr/share/nginx/html
-COPY apps/admin/nginx.conf /etc/nginx/conf.d/default.conf
-EXPOSE 80
-CMD ["nginx", "-g", "daemon off;"]