feat(channel): 缓存扁平化 + 网关映射集成 + 计费模式统一 + 模型限制

- 缓存按 (groupID, platform, model) 三维 key 扁平化，避免跨平台同名模型冲突
- buildCache 批量查询 group platform，按平台过滤展开定价和映射
- model_mapping 改为嵌套格式 {platform: {src: dst}}
- channel_model_pricing 新增 platform 列
- 前端按平台维度重构：每个平台独立配置分组/映射/定价
- 迁移 086: platform 列 + model_mapping 嵌套格式迁移

backend/internal/handler/admin/channel_handler.go

@@ -24,27 +24,28 @@ func NewChannelHandler(channelService *service.ChannelService) *ChannelHandler {
 // --- Request / Response types ---
 
 type createChannelRequest struct {
-	Name               string                         `json:"name" binding:"required,max=100"`
-	Description        string                         `json:"description"`
-	GroupIDs           []int64                        `json:"group_ids"`
-	ModelPricing       []channelModelPricingRequest   `json:"model_pricing"`
-	ModelMapping       map[string]string              `json:"model_mapping"`
-	BillingModelSource string                         `json:"billing_model_source" binding:"omitempty,oneof=requested upstream"`
-	RestrictModels     bool                           `json:"restrict_models"`
+	Name               string                               `json:"name" binding:"required,max=100"`
+	Description        string                               `json:"description"`
+	GroupIDs           []int64                              `json:"group_ids"`
+	ModelPricing       []channelModelPricingRequest         `json:"model_pricing"`
+	ModelMapping       map[string]map[string]string         `json:"model_mapping"`
+	BillingModelSource string                               `json:"billing_model_source" binding:"omitempty,oneof=requested upstream"`
+	RestrictModels     bool                                 `json:"restrict_models"`
 }
 
 type updateChannelRequest struct {
-	Name               string                          `json:"name" binding:"omitempty,max=100"`
-	Description        *string                         `json:"description"`
-	Status             string                          `json:"status" binding:"omitempty,oneof=active disabled"`
-	GroupIDs           *[]int64                        `json:"group_ids"`
-	ModelPricing       *[]channelModelPricingRequest   `json:"model_pricing"`
-	ModelMapping       map[string]string               `json:"model_mapping"`
-	BillingModelSource string                          `json:"billing_model_source" binding:"omitempty,oneof=requested upstream"`
-	RestrictModels     *bool                           `json:"restrict_models"`
+	Name               string                                `json:"name" binding:"omitempty,max=100"`
+	Description        *string                               `json:"description"`
+	Status             string                                `json:"status" binding:"omitempty,oneof=active disabled"`
+	GroupIDs           *[]int64                              `json:"group_ids"`
+	ModelPricing       *[]channelModelPricingRequest         `json:"model_pricing"`
+	ModelMapping       map[string]map[string]string          `json:"model_mapping"`
+	BillingModelSource string                                `json:"billing_model_source" binding:"omitempty,oneof=requested upstream"`
+	RestrictModels     *bool                                 `json:"restrict_models"`
 }
 
 type channelModelPricingRequest struct {
+	Platform         string                     `json:"platform" binding:"omitempty,max=50"`
 	Models           []string                   `json:"models" binding:"required,min=1,max=100"`
 	BillingMode      string                     `json:"billing_mode" binding:"omitempty,oneof=token per_request image"`
 	InputPrice       *float64                   `json:"input_price" binding:"omitempty,min=0"`
@@ -69,21 +70,22 @@ type pricingIntervalRequest struct {
 }
 
 type channelResponse struct {
-	ID                 int64                          `json:"id"`
-	Name               string                         `json:"name"`
-	Description        string                         `json:"description"`
-	Status             string                         `json:"status"`
-	BillingModelSource string                         `json:"billing_model_source"`
-	RestrictModels     bool                           `json:"restrict_models"`
-	GroupIDs           []int64                        `json:"group_ids"`
-	ModelPricing       []channelModelPricingResponse  `json:"model_pricing"`
-	ModelMapping       map[string]string              `json:"model_mapping"`
-	CreatedAt          string                         `json:"created_at"`
-	UpdatedAt          string                         `json:"updated_at"`
+	ID                 int64                                `json:"id"`
+	Name               string                               `json:"name"`
+	Description        string                               `json:"description"`
+	Status             string                               `json:"status"`
+	BillingModelSource string                               `json:"billing_model_source"`
+	RestrictModels     bool                                 `json:"restrict_models"`
+	GroupIDs           []int64                              `json:"group_ids"`
+	ModelPricing       []channelModelPricingResponse        `json:"model_pricing"`
+	ModelMapping       map[string]map[string]string         `json:"model_mapping"`
+	CreatedAt          string                               `json:"created_at"`
+	UpdatedAt          string                               `json:"updated_at"`
 }
 
 type channelModelPricingResponse struct {
 	ID               int64                       `json:"id"`
+	Platform         string                      `json:"platform"`
 	Models           []string                    `json:"models"`
 	BillingMode      string                      `json:"billing_mode"`
 	InputPrice       *float64                    `json:"input_price"`
@@ -131,7 +133,7 @@ func channelToResponse(ch *service.Channel) *channelResponse {
 		resp.GroupIDs = []int64{}
 	}
 	if resp.ModelMapping == nil {
-		resp.ModelMapping = map[string]string{}
+		resp.ModelMapping = map[string]map[string]string{}
 	}
 
 	resp.ModelPricing = make([]channelModelPricingResponse, 0, len(ch.ModelPricing))
@@ -144,6 +146,10 @@ func channelToResponse(ch *service.Channel) *channelResponse {
 		if billingMode == "" {
 			billingMode = "token"
 		}
+		platform := p.Platform
+		if platform == "" {
+			platform = "anthropic"
+		}
 		intervals := make([]pricingIntervalResponse, 0, len(p.Intervals))
 		for _, iv := range p.Intervals {
 			intervals = append(intervals, pricingIntervalResponse{
@@ -161,6 +167,7 @@ func channelToResponse(ch *service.Channel) *channelResponse {
 		}
 		resp.ModelPricing = append(resp.ModelPricing, channelModelPricingResponse{
 			ID:               p.ID,
+			Platform:         platform,
 			Models:           models,
 			BillingMode:      billingMode,
 			InputPrice:       p.InputPrice,
@@ -182,6 +189,10 @@ func pricingRequestToService(reqs []channelModelPricingRequest) []service.Channe
 		if billingMode == "" {
 			billingMode = service.BillingModeToken
 		}
+		platform := r.Platform
+		if platform == "" {
+			platform = "anthropic"
+		}
 		intervals := make([]service.PricingInterval, 0, len(r.Intervals))
 		for _, iv := range r.Intervals {
 			intervals = append(intervals, service.PricingInterval{
@@ -197,6 +208,7 @@ func pricingRequestToService(reqs []channelModelPricingRequest) []service.Channe
 			})
 		}
 		result = append(result, service.ChannelModelPricing{
+			Platform:         platform,
 			Models:           r.Models,
 			BillingMode:      billingMode,
 			InputPrice:       r.InputPrice,

backend/internal/repository/channel_repo.go

@@ -406,8 +406,9 @@ func (r *channelRepository) GetGroupsInOtherChannels(ctx context.Context, channe
 	return conflicting, nil
 }
 
-// marshalModelMapping 将 model mapping 序列化为 JSON 字节，nil/空 map 返回 '{}'
-func marshalModelMapping(m map[string]string) ([]byte, error) {
+// marshalModelMapping 将 model mapping 序列化为嵌套 JSON 字节
+// 格式：{"platform": {"src": "dst"}, ...}
+func marshalModelMapping(m map[string]map[string]string) ([]byte, error) {
 	if len(m) == 0 {
 		return []byte("{}"), nil
 	}
@@ -418,14 +419,43 @@ func marshalModelMapping(m map[string]string) ([]byte, error) {
 	return data, nil
 }
 
-// unmarshalModelMapping 将 JSON 字节反序列化为 model mapping
-func unmarshalModelMapping(data []byte) map[string]string {
+// unmarshalModelMapping 将 JSON 字节反序列化为嵌套 model mapping
+func unmarshalModelMapping(data []byte) map[string]map[string]string {
 	if len(data) == 0 {
 		return nil
 	}
-	var m map[string]string
+	var m map[string]map[string]string
 	if err := json.Unmarshal(data, &m); err != nil {
 		return nil
 	}
 	return m
 }
+
+// GetGroupPlatforms 批量查询分组 ID 对应的平台
+func (r *channelRepository) GetGroupPlatforms(ctx context.Context, groupIDs []int64) (map[int64]string, error) {
+	if len(groupIDs) == 0 {
+		return make(map[int64]string), nil
+	}
+	rows, err := r.db.QueryContext(ctx,
+		`SELECT id, platform FROM groups WHERE id = ANY($1)`,
+		pq.Array(groupIDs),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("get group platforms: %w", err)
+	}
+	defer rows.Close()
+
+	result := make(map[int64]string, len(groupIDs))
+	for rows.Next() {
+		var id int64
+		var platform string
+		if err := rows.Scan(&id, &platform); err != nil {
+			return nil, fmt.Errorf("scan group platform: %w", err)
+		}
+		result[id] = platform
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate group platforms: %w", err)
+	}
+	return result, nil
+}

backend/internal/repository/channel_repo_pricing.go

@@ -15,7 +15,7 @@ import (
 
 func (r *channelRepository) ListModelPricing(ctx context.Context, channelID int64) ([]service.ChannelModelPricing, error) {
 	rows, err := r.db.QueryContext(ctx,
-		`SELECT id, channel_id, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price, created_at, updated_at
+		`SELECT id, channel_id, platform, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price, created_at, updated_at
 		 FROM channel_model_pricing WHERE channel_id = $1 ORDER BY id`, channelID,
 	)
 	if err != nil {
@@ -56,10 +56,10 @@ func (r *channelRepository) UpdateModelPricing(ctx context.Context, pricing *ser
 	}
 	result, err := r.db.ExecContext(ctx,
 		`UPDATE channel_model_pricing
-		 SET models = $1, billing_mode = $2, input_price = $3, output_price = $4, cache_write_price = $5, cache_read_price = $6, image_output_price = $7, per_request_price = $8, updated_at = NOW()
-		 WHERE id = $9`,
+		 SET models = $1, billing_mode = $2, input_price = $3, output_price = $4, cache_write_price = $5, cache_read_price = $6, image_output_price = $7, per_request_price = $8, platform = $9, updated_at = NOW()
+		 WHERE id = $10`,
 		modelsJSON, billingMode, pricing.InputPrice, pricing.OutputPrice, pricing.CacheWritePrice, pricing.CacheReadPrice,
-		pricing.ImageOutputPrice, pricing.PerRequestPrice, pricing.ID,
+		pricing.ImageOutputPrice, pricing.PerRequestPrice, pricing.Platform, pricing.ID,
 	)
 	if err != nil {
 		return fmt.Errorf("update model pricing: %w", err)
@@ -90,7 +90,7 @@ func (r *channelRepository) ReplaceModelPricing(ctx context.Context, channelID i
 // batchLoadModelPricing 批量加载多个渠道的模型定价（含区间）
 func (r *channelRepository) batchLoadModelPricing(ctx context.Context, channelIDs []int64) (map[int64][]service.ChannelModelPricing, error) {
 	rows, err := r.db.QueryContext(ctx,
-		`SELECT id, channel_id, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price, created_at, updated_at
+		`SELECT id, channel_id, platform, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price, created_at, updated_at
 		 FROM channel_model_pricing WHERE channel_id = ANY($1) ORDER BY channel_id, id`,
 		pq.Array(channelIDs),
 	)
@@ -169,7 +169,7 @@ func scanModelPricingRows(rows *sql.Rows) ([]service.ChannelModelPricing, []int6
 		var p service.ChannelModelPricing
 		var modelsJSON []byte
 		if err := rows.Scan(
-			&p.ID, &p.ChannelID, &modelsJSON, &p.BillingMode,
+			&p.ID, &p.ChannelID, &p.Platform, &modelsJSON, &p.BillingMode,
 			&p.InputPrice, &p.OutputPrice, &p.CacheWritePrice, &p.CacheReadPrice,
 			&p.ImageOutputPrice, &p.PerRequestPrice, &p.CreatedAt, &p.UpdatedAt,
 		); err != nil {
@@ -223,10 +223,14 @@ func createModelPricingExec(ctx context.Context, exec dbExec, pricing *service.C
 	if billingMode == "" {
 		billingMode = service.BillingModeToken
 	}
+	platform := pricing.Platform
+	if platform == "" {
+		platform = "anthropic"
+	}
 	err = exec.QueryRowContext(ctx,
-		`INSERT INTO channel_model_pricing (channel_id, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price)
-		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9) RETURNING id, created_at, updated_at`,
-		pricing.ChannelID, modelsJSON, billingMode,
+		`INSERT INTO channel_model_pricing (channel_id, platform, models, billing_mode, input_price, output_price, cache_write_price, cache_read_price, image_output_price, per_request_price)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10) RETURNING id, created_at, updated_at`,
+		pricing.ChannelID, platform, modelsJSON, billingMode,
 		pricing.InputPrice, pricing.OutputPrice, pricing.CacheWritePrice, pricing.CacheReadPrice,
 		pricing.ImageOutputPrice, pricing.PerRequestPrice,
 	).Scan(&pricing.ID, &pricing.CreatedAt, &pricing.UpdatedAt)

backend/internal/service/channel.go

@@ -41,16 +41,17 @@ type Channel struct {
 
 	// 关联的分组 ID 列表
 	GroupIDs []int64
-	// 模型定价列表
+	// 模型定价列表（每条含 Platform 字段）
 	ModelPricing []ChannelModelPricing
-	// 渠道级模型映射
-	ModelMapping map[string]string
+	// 渠道级模型映射（按平台分组：platform → {src→dst}）
+	ModelMapping map[string]map[string]string
 }
 
 // ChannelModelPricing 渠道模型定价条目
 type ChannelModelPricing struct {
 	ID               int64
 	ChannelID        int64
+	Platform         string      // 所属平台（anthropic/openai/gemini/...）
 	Models           []string    // 绑定的模型列表
 	BillingMode      BillingMode // 计费模式
 	InputPrice       *float64    // 每 token 输入价格（USD）— 向后兼容 flat 定价
@@ -82,21 +83,26 @@ type PricingInterval struct {
 }
 
 // ResolveMappedModel 解析渠道级模型映射，返回映射后的模型名。
+// platform 指定查找哪个平台的映射规则。
 // 支持通配符（如 "claude-*" → "claude-sonnet-4"）。
 // 如果没有匹配的映射规则，返回原始模型名。
-func (c *Channel) ResolveMappedModel(requestedModel string) string {
+func (c *Channel) ResolveMappedModel(platform, requestedModel string) string {
 	if len(c.ModelMapping) == 0 {
 		return requestedModel
 	}
+	platformMapping, ok := c.ModelMapping[platform]
+	if !ok || len(platformMapping) == 0 {
+		return requestedModel
+	}
 	lower := strings.ToLower(requestedModel)
 	// 精确匹配优先
-	for src, dst := range c.ModelMapping {
+	for src, dst := range platformMapping {
 		if strings.ToLower(src) == lower {
 			return dst
 		}
 	}
 	// 通配符匹配
-	for src, dst := range c.ModelMapping {
+	for src, dst := range platformMapping {
 		srcLower := strings.ToLower(src)
 		if strings.HasSuffix(srcLower, "*") {
 			prefix := strings.TrimSuffix(srcLower, "*")
@@ -190,9 +196,13 @@ func (c *Channel) Clone() *Channel {
 		}
 	}
 	if c.ModelMapping != nil {
-		cp.ModelMapping = make(map[string]string, len(c.ModelMapping))
-		for k, v := range c.ModelMapping {
-			cp.ModelMapping[k] = v
+		cp.ModelMapping = make(map[string]map[string]string, len(c.ModelMapping))
+		for platform, mapping := range c.ModelMapping {
+			inner := make(map[string]string, len(mapping))
+			for k, v := range mapping {
+				inner[k] = v
+			}
+			cp.ModelMapping[platform] = inner
 		}
 	}
 	return &cp

backend/internal/service/channel_service.go

@@ -39,6 +39,9 @@ type ChannelRepository interface {
 	GetChannelIDByGroupID(ctx context.Context, groupID int64) (int64, error)
 	GetGroupsInOtherChannels(ctx context.Context, channelID int64, groupIDs []int64) ([]int64, error)
 
+	// 分组平台查询
+	GetGroupPlatforms(ctx context.Context, groupIDs []int64) (map[int64]string, error)
+
 	// 模型定价
 	ListModelPricing(ctx context.Context, channelID int64) ([]ChannelModelPricing, error)
 	CreateModelPricing(ctx context.Context, pricing *ChannelModelPricing) error
@@ -47,18 +50,20 @@ type ChannelRepository interface {
 	ReplaceModelPricing(ctx context.Context, channelID int64, pricingList []ChannelModelPricing) error
 }
 
-// channelModelKey 渠道缓存复合键
+// channelModelKey 渠道缓存复合键（显式包含 platform 防止跨平台同名模型冲突）
 type channelModelKey struct {
-	groupID int64
-	model   string // lowercase
+	groupID  int64
+	platform string // 平台标识
+	model    string // lowercase
 }
 
 // channelCache 渠道缓存快照（扁平化哈希结构，热路径 O(1) 查找）
 type channelCache struct {
 	// 热路径查找
-	pricingByGroupModel map[channelModelKey]*ChannelModelPricing // (groupID, model) → 定价
-	mappingByGroupModel map[channelModelKey]string                // (groupID, model) → 映射目标
+	pricingByGroupModel map[channelModelKey]*ChannelModelPricing // (groupID, platform, model) → 定价
+	mappingByGroupModel map[channelModelKey]string                // (groupID, platform, model) → 映射目标
 	channelByGroupID    map[int64]*Channel                        // groupID → 渠道
+	groupPlatform       map[int64]string                          // groupID → platform
 
 	// 冷路径（CRUD 操作）
 	byID     map[int64]*Channel
@@ -135,6 +140,7 @@ func (s *ChannelService) buildCache(ctx context.Context) (*channelCache, error)
 			pricingByGroupModel: make(map[channelModelKey]*ChannelModelPricing),
 			mappingByGroupModel: make(map[channelModelKey]string),
 			channelByGroupID:    make(map[int64]*Channel),
+			groupPlatform:       make(map[int64]string),
 			byID:                make(map[int64]*Channel),
 			loadedAt:            time.Now().Add(channelCacheTTL - channelErrorTTL), // 使剩余 TTL = errorTTL
 		}
@@ -142,10 +148,25 @@ func (s *ChannelService) buildCache(ctx context.Context) (*channelCache, error)
 		return nil, fmt.Errorf("list all channels: %w", err)
 	}
 
+	// 收集所有 groupID，批量查询 platform
+	var allGroupIDs []int64
+	for i := range channels {
+		allGroupIDs = append(allGroupIDs, channels[i].GroupIDs...)
+	}
+	groupPlatforms := make(map[int64]string)
+	if len(allGroupIDs) > 0 {
+		groupPlatforms, err = s.repo.GetGroupPlatforms(dbCtx, allGroupIDs)
+		if err != nil {
+			slog.Warn("failed to load group platforms for channel cache", "error", err)
+			// 降级：继续构建缓存但无法按平台过滤
+		}
+	}
+
 	cache := &channelCache{
 		pricingByGroupModel: make(map[channelModelKey]*ChannelModelPricing),
 		mappingByGroupModel: make(map[channelModelKey]string),
 		channelByGroupID:    make(map[int64]*Channel),
+		groupPlatform:       groupPlatforms,
 		byID:                make(map[int64]*Channel, len(channels)),
 		loadedAt:            time.Now(),
 	}
@@ -157,20 +178,26 @@ func (s *ChannelService) buildCache(ctx context.Context) (*channelCache, error)
 		// 展开到分组维度
 		for _, gid := range ch.GroupIDs {
 			cache.channelByGroupID[gid] = ch
+			platform := groupPlatforms[gid] // e.g. "anthropic"
 
-			// 展开模型定价到 (groupID, model) → *ChannelModelPricing
+			// 只展开该平台的模型定价到 (groupID, platform, model) → *ChannelModelPricing
 			for j := range ch.ModelPricing {
 				pricing := &ch.ModelPricing[j]
+				if pricing.Platform != platform {
+					continue // 跳过非本平台的定价
+				}
 				for _, model := range pricing.Models {
-					key := channelModelKey{groupID: gid, model: strings.ToLower(model)}
+					key := channelModelKey{groupID: gid, platform: platform, model: strings.ToLower(model)}
 					cache.pricingByGroupModel[key] = pricing
 				}
 			}
 
-			// 展开模型映射到 (groupID, model) → target
-			for src, dst := range ch.ModelMapping {
-				key := channelModelKey{groupID: gid, model: strings.ToLower(src)}
-				cache.mappingByGroupModel[key] = dst
+			// 只展开该平台的模型映射到 (groupID, platform, model) → target
+			if platformMapping, ok := ch.ModelMapping[platform]; ok {
+				for src, dst := range platformMapping {
+					key := channelModelKey{groupID: gid, platform: platform, model: strings.ToLower(src)}
+					cache.mappingByGroupModel[key] = dst
+				}
 			}
 		}
 	}
@@ -214,7 +241,8 @@ func (s *ChannelService) GetChannelModelPricing(ctx context.Context, groupID int
 		return nil
 	}
 
-	key := channelModelKey{groupID: groupID, model: strings.ToLower(model)}
+	platform := cache.groupPlatform[groupID]
+	key := channelModelKey{groupID: groupID, platform: platform, model: strings.ToLower(model)}
 	pricing, ok := cache.pricingByGroupModel[key]
 	if !ok {
 		return nil
@@ -246,7 +274,8 @@ func (s *ChannelService) ResolveChannelMapping(ctx context.Context, groupID int6
 		result.BillingModelSource = BillingModelSourceRequested
 	}
 
-	key := channelModelKey{groupID: groupID, model: strings.ToLower(model)}
+	platform := cache.groupPlatform[groupID]
+	key := channelModelKey{groupID: groupID, platform: platform, model: strings.ToLower(model)}
 	if mapped, ok := cache.mappingByGroupModel[key]; ok {
 		result.MappedModel = mapped
 		result.Mapped = true
@@ -270,7 +299,8 @@ func (s *ChannelService) IsModelRestricted(ctx context.Context, groupID int64, m
 	}
 
 	// 检查模型是否在定价列表中
-	key := channelModelKey{groupID: groupID, model: strings.ToLower(model)}
+	platform := cache.groupPlatform[groupID]
+	key := channelModelKey{groupID: groupID, platform: platform, model: strings.ToLower(model)}
 	_, exists := cache.pricingByGroupModel[key]
 	return !exists
 }
@@ -458,7 +488,7 @@ type CreateChannelInput struct {
 	Description        string
 	GroupIDs           []int64
 	ModelPricing       []ChannelModelPricing
-	ModelMapping       map[string]string
+	ModelMapping       map[string]map[string]string // platform → {src→dst}
 	BillingModelSource string
 	RestrictModels     bool
 }
@@ -470,7 +500,7 @@ type UpdateChannelInput struct {
 	Status             string
 	GroupIDs           *[]int64
 	ModelPricing       *[]ChannelModelPricing
-	ModelMapping       map[string]string
+	ModelMapping       map[string]map[string]string // platform → {src→dst}
 	BillingModelSource string
 	RestrictModels     *bool
 }

backend/migrations/086_channel_platform_pricing.sql

@@ -0,0 +1,21 @@
+-- 086_channel_platform_pricing.sql
+-- 渠道按平台维度：model_pricing 加 platform 列，model_mapping 改为嵌套格式
+
+-- 1. channel_model_pricing 加 platform 列
+ALTER TABLE channel_model_pricing
+    ADD COLUMN IF NOT EXISTS platform VARCHAR(50) NOT NULL DEFAULT 'anthropic';
+
+CREATE INDEX IF NOT EXISTS idx_channel_model_pricing_platform
+    ON channel_model_pricing (platform);
+
+-- 2. model_mapping: 从扁平 {"src":"dst"} 迁移为嵌套 {"anthropic":{"src":"dst"}}
+-- 仅迁移非空、非 '{}' 的旧格式数据（通过检查第一个 value 是否为字符串来判断是否为旧格式）
+UPDATE channels
+SET model_mapping = jsonb_build_object('anthropic', model_mapping)
+WHERE model_mapping IS NOT NULL
+  AND model_mapping::text NOT IN ('{}', 'null', '')
+  AND NOT EXISTS (
+      SELECT 1 FROM jsonb_each(model_mapping) AS kv
+      WHERE jsonb_typeof(kv.value) = 'object'
+      LIMIT 1
+  );