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/src/types.ts

@@ -0,0 +1,70 @@
+export interface ProductSummary {
+  id: string;
+  gtin: string | null;
+  name: string;
+  brand: string | null;
+  category_path: string | null;
+}
+
+export interface Product {
+  id: string;
+  gtin: string | null;
+  name: string;
+  brand: string | null;
+  category_path: string | null;
+  net_content_value: number | null;
+  net_content_unit: string | null;
+  country_of_origin: string | null;
+  quality_score: number;
+  nutriments?: Record<string, unknown> | null;
+  nutrition_basis?: string | null;
+  nutri_score?: string | null;
+  ingredients_text?: string | null;
+  allergens?: string[] | null;
+  additives?: string[] | null;
+}
+
+export interface Category {
+  id: string;
+  name_zh: string;
+  name_en: string | null;
+  path: string;
+  level: number;
+}
+
+export interface SubmissionImage {
+  url: string;
+  kind: string;
+}
+
+export interface SubmissionInput {
+  gtin?: string | null;
+  name: string;
+  brand_name?: string | null;
+  category_id?: string | null;
+  net_content_value?: number | null;
+  net_content_unit?: string | null;
+  country_of_origin?: string | null;
+  ingredients_text?: string | null;
+  nutriments?: Record<string, number> | null;
+  nutrition_basis?: string | null;
+  serving_size?: string | null;
+  nutri_score?: string | null;
+  images?: SubmissionImage[];
+  submitter_name?: string | null;
+  submitter_contact?: string | null;
+  note?: string | null;
+}
+
+export const NUTRIMENT_LABELS: Record<string, string> = {
+  energy_kcal: "能量 (kcal)",
+  energy_kj: "能量 (kJ)",
+  fat: "脂肪 (g)",
+  saturated_fat: "饱和脂肪 (g)",
+  carbohydrates: "碳水 (g)",
+  sugars: "糖 (g)",
+  proteins: "蛋白质 (g)",
+  salt: "盐 (g)",
+  sodium: "钠 (g)",
+  fiber: "膳食纤维 (g)",
+};