feat: 公开首页(搜索+商品详情) + 好心人投稿 + 后台审核收纳

- 公开前端 SPA（根路径 /）：首页大搜索框、检索结果、只读商品详情、贡献档案表单
- 公开写入端点 POST /api/public/submissions（无需登录，基础频率限流），投稿进入 submission 待审核队列，不直接写 product
- 迁移 0006：submission 投稿表 + community 来源(trust=0.50)
- 后台审核队列：列表(待审核/已通过/已驳回) → 查看投稿 → 通过(创建/补全商品 + 记 source=community + 字段级溯源 + 审计 + 重算质量分) / 驳回(记原因)
- 公开只读 api 服务内嵌公开 SPA；Dockerfile.prod 增加 node 构建阶段 + 内嵌 dist

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

public-frontend/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "opengoods-public-frontend",
+  "private": true,
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "lucide-react": "^0.344.0"
+  },
+  "devDependencies": {
+    "@types/react": "^18.2.55",
+    "@types/react-dom": "^18.2.19",
+    "@vitejs/plugin-react": "^4.2.1",
+    "autoprefixer": "^10.4.17",
+    "postcss": "^8.4.35",
+    "tailwindcss": "^3.4.1",
+    "typescript": "^5.3.3",
+    "vite": "^5.1.0"
+  }
+}