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/handler/setting_handler.go

@@ -1,47 +1,47 @@
-package handler
-
-import (
-	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
-	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
-	"github.com/Wei-Shaw/sub2api/internal/service"
-
-	"github.com/gin-gonic/gin"
-)
-
-// SettingHandler 公开设置处理器（无需认证）
-type SettingHandler struct {
-	settingService *service.SettingService
-	version        string
-}
-
-// NewSettingHandler 创建公开设置处理器
-func NewSettingHandler(settingService *service.SettingService, version string) *SettingHandler {
-	return &SettingHandler{
-		settingService: settingService,
-		version:        version,
-	}
-}
-
-// GetPublicSettings 获取公开设置
-// GET /api/v1/settings/public
-func (h *SettingHandler) GetPublicSettings(c *gin.Context) {
-	settings, err := h.settingService.GetPublicSettings(c.Request.Context())
-	if err != nil {
-		response.ErrorFrom(c, err)
-		return
-	}
-
-	response.Success(c, dto.PublicSettings{
-		RegistrationEnabled: settings.RegistrationEnabled,
-		EmailVerifyEnabled:  settings.EmailVerifyEnabled,
-		TurnstileEnabled:    settings.TurnstileEnabled,
-		TurnstileSiteKey:    settings.TurnstileSiteKey,
-		SiteName:            settings.SiteName,
-		SiteLogo:            settings.SiteLogo,
-		SiteSubtitle:        settings.SiteSubtitle,
-		ApiBaseUrl:          settings.ApiBaseUrl,
-		ContactInfo:         settings.ContactInfo,
-		DocUrl:              settings.DocUrl,
-		Version:             h.version,
-	})
-}
+package handler
+
+import (
+	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// SettingHandler 公开设置处理器（无需认证）
+type SettingHandler struct {
+	settingService *service.SettingService
+	version        string
+}
+
+// NewSettingHandler 创建公开设置处理器
+func NewSettingHandler(settingService *service.SettingService, version string) *SettingHandler {
+	return &SettingHandler{
+		settingService: settingService,
+		version:        version,
+	}
+}
+
+// GetPublicSettings 获取公开设置
+// GET /api/v1/settings/public
+func (h *SettingHandler) GetPublicSettings(c *gin.Context) {
+	settings, err := h.settingService.GetPublicSettings(c.Request.Context())
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+
+	response.Success(c, dto.PublicSettings{
+		RegistrationEnabled: settings.RegistrationEnabled,
+		EmailVerifyEnabled:  settings.EmailVerifyEnabled,
+		TurnstileEnabled:    settings.TurnstileEnabled,
+		TurnstileSiteKey:    settings.TurnstileSiteKey,
+		SiteName:            settings.SiteName,
+		SiteLogo:            settings.SiteLogo,
+		SiteSubtitle:        settings.SiteSubtitle,
+		ApiBaseUrl:          settings.ApiBaseUrl,
+		ContactInfo:         settings.ContactInfo,
+		DocUrl:              settings.DocUrl,
+		Version:             h.version,
+	})
+}