feat: 可扩展档案模式框架 + 内置 3C(电子) 模式

- 新增 category.archive_kind 与 kind_field 字段模板表（迁移 0010）
- 种子 electronics 字段模板 + 3C 品类树（手机/笔记本/平板等）
- 后端按档案模式动态计算完整度/合格：食品沿用 food_detail，
  其它模式走 product.attributes + kind_field
- 新增 GET /api/kind-fields?kind= 接口
- 后台编辑页按品类模式动态渲染规格参数表单
- 公开详情页/接口输出带标签的规格表

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

api/internal/store/store.go

@@ -4,8 +4,10 @@ package store
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"strconv"
+	"strings"
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
@@ -56,6 +58,15 @@ type Barcode struct {
 	IsPrimary bool    `json:"is_primary"`
 }
 
+// ProductSpec is one labeled spec line for a non-food product, rendered from
+// the product's attributes JSONB against its archive kind's field template.
+type ProductSpec struct {
+	Key   string `json:"key"`
+	Label string `json:"label"`
+	Value string `json:"value"`
+	Unit  string `json:"unit,omitempty"`
+}
+
 // Product is the full public view of a product.
 type Product struct {
 	ID              string         `json:"id"`
@@ -64,11 +75,13 @@ type Product struct {
 	Brand           *string        `json:"brand"`
 	CategoryPath    *string        `json:"category_path"`
 	GPCBrickCode    *string        `json:"gpc_brick_code"`
+	ArchiveKind     string         `json:"archive_kind"`
 	NetContentValue *float64       `json:"net_content_value"`
 	NetContentUnit  *string        `json:"net_content_unit"`
 	CountryOfOrigin *string        `json:"country_of_origin"`
 	QualityScore    float64        `json:"quality_score"`
 	Barcodes        []Barcode      `json:"barcodes"`
+	Specs           []ProductSpec  `json:"specs,omitempty"`
 	Nutriments      map[string]any `json:"nutriments,omitempty"`
 	NutritionBasis  *string        `json:"nutrition_basis,omitempty"`
 	NutriScore      *string        `json:"nutri_score,omitempty"`
@@ -120,6 +133,7 @@ type SearchFilters struct {
 
 const productSelect = `
 SELECT p.id, p.gtin, p.name, b.name, c.path::text, p.gpc_brick_code,
+       COALESCE(c.archive_kind, 'generic'), p.attributes,
        p.net_content_value, p.net_content_unit, p.country_of_origin, p.quality_score,
        f.nutriments, f.nutrition_basis, f.nutri_score, f.ingredients_text,
        f.allergens, f.additives
@@ -129,21 +143,81 @@ LEFT JOIN category c ON c.id = p.category_id
 LEFT JOIN food_detail f ON f.product_id = p.id
 `
 
-func scanProduct(row pgx.Row) (*Product, error) {
+func scanProduct(row pgx.Row) (*Product, []byte, error) {
 	var p Product
+	var attributes []byte
 	err := row.Scan(
 		&p.ID, &p.GTIN, &p.Name, &p.Brand, &p.CategoryPath, &p.GPCBrickCode,
+		&p.ArchiveKind, &attributes,
 		&p.NetContentValue, &p.NetContentUnit, &p.CountryOfOrigin, &p.QualityScore,
 		&p.Nutriments, &p.NutritionBasis, &p.NutriScore, &p.Ingredients,
 		&p.Allergens, &p.Additives,
 	)
 	if errors.Is(err, pgx.ErrNoRows) {
-		return nil, ErrNotFound
+		return nil, nil, ErrNotFound
 	}
+	if err != nil {
+		return nil, nil, err
+	}
+	return &p, attributes, nil
+}
+
+// buildSpecs renders the labeled, ordered spec list for a non-food product from
+// its attributes JSONB against its archive kind's field template.
+func (s *Store) buildSpecs(ctx context.Context, kind string, attributes []byte) ([]ProductSpec, error) {
+	if kind == "" || kind == "food" || len(attributes) == 0 {
+		return nil, nil
+	}
+	attrs := map[string]any{}
+	if err := json.Unmarshal(attributes, &attrs); err != nil || len(attrs) == 0 {
+		return nil, nil
+	}
+	rows, err := s.pool.Query(ctx,
+		"SELECT field_key, label_zh, COALESCE(unit, '') FROM kind_field WHERE kind = $1 ORDER BY sort_order, field_key", kind)
 	if err != nil {
 		return nil, err
 	}
-	return &p, nil
+	defer rows.Close()
+	specs := []ProductSpec{}
+	for rows.Next() {
+		var key, label, unit string
+		if err := rows.Scan(&key, &label, &unit); err != nil {
+			return nil, err
+		}
+		v, ok := attrs[key]
+		if !ok || v == nil {
+			continue
+		}
+		val := stringifyAttr(v)
+		if val == "" {
+			continue
+		}
+		specs = append(specs, ProductSpec{Key: key, Label: label, Value: val, Unit: unit})
+	}
+	return specs, rows.Err()
+}
+
+// stringifyAttr renders a JSON attribute value as display text.
+func stringifyAttr(v any) string {
+	switch t := v.(type) {
+	case string:
+		return t
+	case float64:
+		return strconv.FormatFloat(t, 'f', -1, 64)
+	case bool:
+		if t {
+			return "是"
+		}
+		return "否"
+	case []any:
+		parts := make([]string, 0, len(t))
+		for _, e := range t {
+			parts = append(parts, stringifyAttr(e))
+		}
+		return strings.Join(parts, "、")
+	default:
+		return ""
+	}
 }
 
 // ProductByGTIN looks up an active product by any of its barcodes.
@@ -154,26 +228,32 @@ func (s *Store) ProductByGTIN(ctx context.Context, gtin string) (*Product, error
          SELECT 1 FROM product_barcode pb
          WHERE pb.product_id = p.id AND pb.gtin = $1))
  LIMIT 1`, gtin)
-	p, err := scanProduct(row)
+	p, attrs, err := scanProduct(row)
 	if err != nil {
 		return nil, err
 	}
 	if p.Barcodes, err = s.ProductBarcodes(ctx, p.ID); err != nil {
 		return nil, err
 	}
+	if p.Specs, err = s.buildSpecs(ctx, p.ArchiveKind, attrs); err != nil {
+		return nil, err
+	}
 	return p, nil
 }
 
 // ProductByID looks up a product by its UUID.
 func (s *Store) ProductByID(ctx context.Context, id string) (*Product, error) {
 	row := s.pool.QueryRow(ctx, productSelect+" WHERE p.id = $1", id)
-	p, err := scanProduct(row)
+	p, attrs, err := scanProduct(row)
 	if err != nil {
 		return nil, err
 	}
 	if p.Barcodes, err = s.ProductBarcodes(ctx, p.ID); err != nil {
 		return nil, err
 	}
+	if p.Specs, err = s.buildSpecs(ctx, p.ArchiveKind, attrs); err != nil {
+		return nil, err
+	}
 	return p, nil
 }