sync: bring over remaining release/custom-0.1.115 changes

- Extract PublicSettingsInjectionPayload named struct with drift test
- Add channel_monitor_default_interval_seconds to SSR injection
- Add image_output_price to SupportedModelChip
- Simplify AppSidebar buildSelfNavItems (admins see available channels)
- Add gateway WARN logs for 503 no-available-accounts branches
- Wire ChannelMonitorRunner into provideCleanup for graceful shutdown
- Add migrations 130/131 (CC template userid fix + mimicry field cleanup)
- Clean up fork-only features (sora, claude max simulation, client affinity)
- Remove ~320 obsolete i18n keys
- Add codexUsage utility, WechatServiceButton, BulkEditAccountModal
- Tidy go.sum

backend/ent/schema/group.go

@@ -33,8 +33,6 @@ func (Group) Mixin() []ent.Mixin {
 
 func (Group) Fields() []ent.Field {
 	return []ent.Field{
-		// 唯一约束通过部分索引实现（WHERE deleted_at IS NULL），支持软删除后重用
-		// 见迁移文件 016_soft_delete_partial_unique_indexes.sql
 		field.String("name").
 			MaxLen(100).
 			NotEmpty(),
@@ -51,7 +49,6 @@ func (Group) Fields() []ent.Field {
 			MaxLen(20).
 			Default(domain.StatusActive),
 
-		// Subscription-related fields (added by migration 003)
 		field.String("platform").
 			MaxLen(50).
 			Default(domain.PlatformAnthropic),
@@ -73,7 +70,6 @@ func (Group) Fields() []ent.Field {
 		field.Int("default_validity_days").
 			Default(30),
 
-		// 图片生成计费配置（antigravity 和 gemini 平台使用）
 		field.Float("image_price_1k").
 			Optional().
 			Nillable().
@@ -90,42 +86,36 @@ func (Group) Fields() []ent.Field {
 		// Claude Code 客户端限制 (added by migration 029)
 		field.Bool("claude_code_only").
 			Default(false).
-			Comment("是否仅允许 Claude Code 客户端"),
+			Comment("allow Claude Code client only"),
 		field.Int64("fallback_group_id").
 			Optional().
 			Nillable().
-			Comment("非 Claude Code 请求降级使用的分组 ID"),
+			Comment("fallback group for non-Claude-Code requests"),
 		field.Int64("fallback_group_id_on_invalid_request").
 			Optional().
 			Nillable().
-			Comment("无效请求兜底使用的分组 ID"),
+			Comment("fallback group for invalid request"),
 
-		// 模型路由配置 (added by migration 040)
 		field.JSON("model_routing", map[string][]int64{}).
 			Optional().
 			SchemaType(map[string]string{dialect.Postgres: "jsonb"}).
-			Comment("模型路由配置：模型模式 -> 优先账号ID列表"),
-
-		// 模型路由开关 (added by migration 041)
+			Comment("model routing config: pattern -> account ids"),
 		field.Bool("model_routing_enabled").
 			Default(false).
-			Comment("是否启用模型路由配置"),
+			Comment("whether model routing is enabled"),
 
-		// MCP XML 协议注入开关 (added by migration 042)
 		field.Bool("mcp_xml_inject").
 			Default(true).
-			Comment("是否注入 MCP XML 调用协议提示词（仅 antigravity 平台）"),
+			Comment("whether MCP XML prompt injection is enabled"),
 
-		// 支持的模型系列 (added by migration 046)
 		field.JSON("supported_model_scopes", []string{}).
 			Default([]string{"claude", "gemini_text", "gemini_image"}).
 			SchemaType(map[string]string{dialect.Postgres: "jsonb"}).
-			Comment("支持的模型系列：claude, gemini_text, gemini_image"),
+			Comment("supported model scopes: claude, gemini_text, gemini_image"),
 
-		// 分组排序 (added by migration 052)
 		field.Int("sort_order").
 			Default(0).
-			Comment("分组显示排序，数值越小越靠前"),
+			Comment("group display order, lower comes first"),
 
 		// OpenAI Messages 调度配置 (added by migration 069)
 		field.Bool("allow_messages_dispatch").
@@ -160,14 +150,11 @@ func (Group) Edges() []ent.Edge {
 		edge.From("allowed_users", User.Type).
 			Ref("allowed_groups").
 			Through("user_allowed_groups", UserAllowedGroup.Type),
-		// 注意：fallback_group_id 直接作为字段使用，不定义 edge
-		// 这样允许多个分组指向同一个降级分组（M2O 关系）
 	}
 }
 
 func (Group) Indexes() []ent.Index {
 	return []ent.Index{
-		// name 字段已在 Fields() 中声明 Unique()，无需重复索引
 		index.Fields("status"),
 		index.Fields("platform"),
 		index.Fields("subscription_type"),