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/repository/db_pool.go

@@ -1,32 +1,32 @@
-package repository
-
-import (
-	"database/sql"
-	"time"
-
-	"github.com/Wei-Shaw/sub2api/internal/config"
-)
-
-type dbPoolSettings struct {
-	MaxOpenConns    int
-	MaxIdleConns    int
-	ConnMaxLifetime time.Duration
-	ConnMaxIdleTime time.Duration
-}
-
-func buildDBPoolSettings(cfg *config.Config) dbPoolSettings {
-	return dbPoolSettings{
-		MaxOpenConns:    cfg.Database.MaxOpenConns,
-		MaxIdleConns:    cfg.Database.MaxIdleConns,
-		ConnMaxLifetime: time.Duration(cfg.Database.ConnMaxLifetimeMinutes) * time.Minute,
-		ConnMaxIdleTime: time.Duration(cfg.Database.ConnMaxIdleTimeMinutes) * time.Minute,
-	}
-}
-
-func applyDBPoolSettings(db *sql.DB, cfg *config.Config) {
-	settings := buildDBPoolSettings(cfg)
-	db.SetMaxOpenConns(settings.MaxOpenConns)
-	db.SetMaxIdleConns(settings.MaxIdleConns)
-	db.SetConnMaxLifetime(settings.ConnMaxLifetime)
-	db.SetConnMaxIdleTime(settings.ConnMaxIdleTime)
-}
+package repository
+
+import (
+	"database/sql"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+)
+
+type dbPoolSettings struct {
+	MaxOpenConns    int
+	MaxIdleConns    int
+	ConnMaxLifetime time.Duration
+	ConnMaxIdleTime time.Duration
+}
+
+func buildDBPoolSettings(cfg *config.Config) dbPoolSettings {
+	return dbPoolSettings{
+		MaxOpenConns:    cfg.Database.MaxOpenConns,
+		MaxIdleConns:    cfg.Database.MaxIdleConns,
+		ConnMaxLifetime: time.Duration(cfg.Database.ConnMaxLifetimeMinutes) * time.Minute,
+		ConnMaxIdleTime: time.Duration(cfg.Database.ConnMaxIdleTimeMinutes) * time.Minute,
+	}
+}
+
+func applyDBPoolSettings(db *sql.DB, cfg *config.Config) {
+	settings := buildDBPoolSettings(cfg)
+	db.SetMaxOpenConns(settings.MaxOpenConns)
+	db.SetMaxIdleConns(settings.MaxIdleConns)
+	db.SetConnMaxLifetime(settings.ConnMaxLifetime)
+	db.SetConnMaxIdleTime(settings.ConnMaxIdleTime)
+}