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/server/routes/auth.go

@@ -1,36 +1,36 @@
-package routes
-
-import (
-	"github.com/Wei-Shaw/sub2api/internal/handler"
-	"github.com/Wei-Shaw/sub2api/internal/server/middleware"
-
-	"github.com/gin-gonic/gin"
-)
-
-// RegisterAuthRoutes 注册认证相关路由
-func RegisterAuthRoutes(
-	v1 *gin.RouterGroup,
-	h *handler.Handlers,
-	jwtAuth middleware.JWTAuthMiddleware,
-) {
-	// 公开接口
-	auth := v1.Group("/auth")
-	{
-		auth.POST("/register", h.Auth.Register)
-		auth.POST("/login", h.Auth.Login)
-		auth.POST("/send-verify-code", h.Auth.SendVerifyCode)
-	}
-
-	// 公开设置（无需认证）
-	settings := v1.Group("/settings")
-	{
-		settings.GET("/public", h.Setting.GetPublicSettings)
-	}
-
-	// 需要认证的当前用户信息
-	authenticated := v1.Group("")
-	authenticated.Use(gin.HandlerFunc(jwtAuth))
-	{
-		authenticated.GET("/auth/me", h.Auth.GetCurrentUser)
-	}
-}
+package routes
+
+import (
+	"github.com/Wei-Shaw/sub2api/internal/handler"
+	"github.com/Wei-Shaw/sub2api/internal/server/middleware"
+
+	"github.com/gin-gonic/gin"
+)
+
+// RegisterAuthRoutes 注册认证相关路由
+func RegisterAuthRoutes(
+	v1 *gin.RouterGroup,
+	h *handler.Handlers,
+	jwtAuth middleware.JWTAuthMiddleware,
+) {
+	// 公开接口
+	auth := v1.Group("/auth")
+	{
+		auth.POST("/register", h.Auth.Register)
+		auth.POST("/login", h.Auth.Login)
+		auth.POST("/send-verify-code", h.Auth.SendVerifyCode)
+	}
+
+	// 公开设置（无需认证）
+	settings := v1.Group("/settings")
+	{
+		settings.GET("/public", h.Setting.GetPublicSettings)
+	}
+
+	// 需要认证的当前用户信息
+	authenticated := v1.Group("")
+	authenticated.Use(gin.HandlerFunc(jwtAuth))
+	{
+		authenticated.GET("/auth/me", h.Auth.GetCurrentUser)
+	}
+}