fix: preserve group pricing in auth snapshots

backend/internal/service/api_key_auth_cache.go

@@ -84,6 +84,8 @@ type APIKeyAuthGroupSnapshot struct {
 	AudioRealtimePricePerMin        *float64                      `json:"audio_realtime_price_per_min,omitempty"`
 	AudioTTSPricePerMillionChars    *float64                      `json:"audio_tts_price_per_million_chars,omitempty"`
 	AudioSTTPricePerHour            *float64                      `json:"audio_stt_price_per_hour,omitempty"`
+	LongContextPricingEnabled       bool                          `json:"long_context_pricing_enabled"`
+	ModelPricing                    []ChannelModelPricing         `json:"model_pricing,omitempty"`
 	ClaudeCodeOnly                  bool                          `json:"claude_code_only"`
 	FallbackGroupID                 *int64                        `json:"fallback_group_id,omitempty"`
 	FallbackGroupIDOnInvalidRequest *int64                        `json:"fallback_group_id_on_invalid_request,omitempty"`

backend/internal/service/api_key_auth_cache_impl.go

@@ -14,7 +14,7 @@ import (
 	"github.com/dgraph-io/ristretto"
 )
 
-const apiKeyAuthSnapshotVersion = 19 // v19: group search/audio/video_model_prices billing fields (force refresh of pre-fix snapshots)
+const apiKeyAuthSnapshotVersion = 20 // v20: group long-context and model pricing fields (force refresh of pre-fix snapshots)
 
 type apiKeyAuthCacheConfig struct {
 	l1Size        int
@@ -406,6 +406,8 @@ func (s *APIKeyService) snapshotFromAPIKey(ctx context.Context, apiKey *APIKey)
 			AudioRealtimePricePerMin:        apiKey.Group.AudioRealtimePricePerMin,
 			AudioTTSPricePerMillionChars:    apiKey.Group.AudioTTSPricePerMillionChars,
 			AudioSTTPricePerHour:            apiKey.Group.AudioSTTPricePerHour,
+			LongContextPricingEnabled:       apiKey.Group.LongContextPricingEnabled,
+			ModelPricing:                    apiKey.Group.ModelPricing,
 			ClaudeCodeOnly:                  apiKey.Group.ClaudeCodeOnly,
 			FallbackGroupID:                 apiKey.Group.FallbackGroupID,
 			FallbackGroupIDOnInvalidRequest: apiKey.Group.FallbackGroupIDOnInvalidRequest,
@@ -501,6 +503,8 @@ func (s *APIKeyService) snapshotToAPIKey(key string, snapshot *APIKeyAuthSnapsho
 			AudioRealtimePricePerMin:        snapshot.Group.AudioRealtimePricePerMin,
 			AudioTTSPricePerMillionChars:    snapshot.Group.AudioTTSPricePerMillionChars,
 			AudioSTTPricePerHour:            snapshot.Group.AudioSTTPricePerHour,
+			LongContextPricingEnabled:       snapshot.Group.LongContextPricingEnabled,
+			ModelPricing:                    snapshot.Group.ModelPricing,
 			ClaudeCodeOnly:                  snapshot.Group.ClaudeCodeOnly,
 			FallbackGroupID:                 snapshot.Group.FallbackGroupID,
 			FallbackGroupIDOnInvalidRequest: snapshot.Group.FallbackGroupIDOnInvalidRequest,

backend/internal/service/api_key_auth_cache_pricing_test.go

@@ -0,0 +1,50 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAPIKeyAuthSnapshotGroupPricingRoundtrip(t *testing.T) {
+	groupID := int64(50)
+	inputPrice := 1e-6
+	outputPrice := 2e-6
+	apiKey := &APIKey{
+		ID: 82, UserID: 40, GroupID: &groupID, Key: "sk-pricing-roundtrip", Status: StatusActive,
+		User: &User{ID: 40, Status: StatusActive},
+		Group: &Group{
+			ID: groupID, Name: "pricing-roundtrip", Platform: PlatformAnthropic, Status: StatusActive,
+			LongContextPricingEnabled: true,
+			ModelPricing: []ChannelModelPricing{{
+				Models: []string{"claude-sonnet-*"}, BillingMode: BillingModeToken,
+				InputPrice: &inputPrice, OutputPrice: &outputPrice,
+			}},
+		},
+	}
+	svc := &APIKeyService{}
+
+	payload, err := json.Marshal(&APIKeyAuthCacheEntry{Snapshot: svc.snapshotFromAPIKey(context.Background(), apiKey)})
+	require.NoError(t, err)
+	var cached APIKeyAuthCacheEntry
+	require.NoError(t, json.Unmarshal(payload, &cached))
+
+	materialized, used, err := svc.applyAuthCacheEntry(apiKey.Key, &cached)
+	require.NoError(t, err)
+	require.True(t, used)
+	require.NotNil(t, materialized.Group)
+	require.True(t, materialized.Group.LongContextPricingEnabled)
+	require.Equal(t, apiKey.Group.ModelPricing, materialized.Group.ModelPricing)
+
+	billing := &BillingService{fallbackPrices: map[string]*ModelPricing{
+		"claude-sonnet-4": {InputPricePerToken: 3e-6, OutputPricePerToken: 15e-6},
+	}}
+	resolver := NewModelPricingResolver(nil, billing)
+	resolved := resolver.Resolve(context.Background(), PricingInput{Model: "claude-sonnet-4", Group: materialized.Group})
+	require.Equal(t, PricingSourceGroup, resolved.Source)
+	require.True(t, resolved.longContextPricingEnabled)
+	require.InDelta(t, inputPrice, resolved.BasePricing.InputPricePerToken, 1e-12)
+	require.InDelta(t, outputPrice, resolved.BasePricing.OutputPricePerToken, 1e-12)
+}

backend/internal/service/api_key_auth_cache_profit_test.go

@@ -53,7 +53,7 @@ func TestAPIKeyAuthSnapshotProfitControlRoundtrip(t *testing.T) {
 	snapshot := svc.snapshotFromAPIKey(context.Background(), apiKey)
 	require.NotNil(t, snapshot)
 	require.Equal(t, apiKeyAuthSnapshotVersion, snapshot.Version)
-	require.Equal(t, 19, snapshot.Version, "v19 起认证快照携带 search/audio/video_model_prices 计费字段")
+	require.Equal(t, 20, snapshot.Version, "v20 起认证快照携带分组长上下文与模型定价字段")
 
 	// 模拟 L2 缓存的完整 JSON 往返（与 apiKeyCache.SetAuthCache/GetAuthCache 同构）。
 	payload, err := json.Marshal(&APIKeyAuthCacheEntry{Snapshot: snapshot})