feat: 品牌重命名 Sub2API -> TianShuAPI

- 前端: 所有界面显示、i18n 文本、组件中的品牌名称
- 后端: 服务层、设置默认值、邮件模板、安装向导
- 数据库: 迁移脚本注释
- 保持功能完全一致，仅更改品牌名称

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/internal/service/gateway_service_benchmark_test.go

@@ -1,50 +1,50 @@
-package service
-
-import (
-	"strconv"
-	"testing"
-)
-
-var benchmarkStringSink string
-
-// BenchmarkGenerateSessionHash_Metadata 关注 JSON 解析与正则匹配开销。
-func BenchmarkGenerateSessionHash_Metadata(b *testing.B) {
-	svc := &GatewayService{}
-	body := []byte(`{"metadata":{"user_id":"session_123e4567-e89b-12d3-a456-426614174000"},"messages":[{"content":"hello"}]}`)
-
-	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
-		parsed, err := ParseGatewayRequest(body)
-		if err != nil {
-			b.Fatalf("解析请求失败: %v", err)
-		}
-		benchmarkStringSink = svc.GenerateSessionHash(parsed)
-	}
-}
-
-// BenchmarkExtractCacheableContent_System 关注字符串拼接路径的性能。
-func BenchmarkExtractCacheableContent_System(b *testing.B) {
-	svc := &GatewayService{}
-	req := buildSystemCacheableRequest(12)
-
-	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
-		benchmarkStringSink = svc.extractCacheableContent(req)
-	}
-}
-
-func buildSystemCacheableRequest(parts int) *ParsedRequest {
-	systemParts := make([]any, 0, parts)
-	for i := 0; i < parts; i++ {
-		systemParts = append(systemParts, map[string]any{
-			"text": "system_part_" + strconv.Itoa(i),
-			"cache_control": map[string]any{
-				"type": "ephemeral",
-			},
-		})
-	}
-	return &ParsedRequest{
-		System:    systemParts,
-		HasSystem: true,
-	}
-}
+package service
+
+import (
+	"strconv"
+	"testing"
+)
+
+var benchmarkStringSink string
+
+// BenchmarkGenerateSessionHash_Metadata 关注 JSON 解析与正则匹配开销。
+func BenchmarkGenerateSessionHash_Metadata(b *testing.B) {
+	svc := &GatewayService{}
+	body := []byte(`{"metadata":{"user_id":"session_123e4567-e89b-12d3-a456-426614174000"},"messages":[{"content":"hello"}]}`)
+
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		parsed, err := ParseGatewayRequest(body)
+		if err != nil {
+			b.Fatalf("解析请求失败: %v", err)
+		}
+		benchmarkStringSink = svc.GenerateSessionHash(parsed)
+	}
+}
+
+// BenchmarkExtractCacheableContent_System 关注字符串拼接路径的性能。
+func BenchmarkExtractCacheableContent_System(b *testing.B) {
+	svc := &GatewayService{}
+	req := buildSystemCacheableRequest(12)
+
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		benchmarkStringSink = svc.extractCacheableContent(req)
+	}
+}
+
+func buildSystemCacheableRequest(parts int) *ParsedRequest {
+	systemParts := make([]any, 0, parts)
+	for i := 0; i < parts; i++ {
+		systemParts = append(systemParts, map[string]any{
+			"text": "system_part_" + strconv.Itoa(i),
+			"cache_control": map[string]any{
+				"type": "ephemeral",
+			},
+		})
+	}
+	return &ParsedRequest{
+		System:    systemParts,
+		HasSystem: true,
+	}
+}