feat(handler): 添加 Gemini OAuth Handler 和完善依赖注入

- 新增 Gemini OAuth 授权处理器
- 扩展账号和网关处理器支持 Gemini
- 注册 Gemini 相关路由
- 更新 Wire 依赖注入配置（所有层）
- 更新 Docker Compose 配置

backend/internal/handler/admin/account_handler.go

@@ -30,6 +30,7 @@ type AccountHandler struct {
 	adminService        service.AdminService
 	oauthService        *service.OAuthService
 	openaiOAuthService  *service.OpenAIOAuthService
+	geminiOAuthService  *service.GeminiOAuthService
 	rateLimitService    *service.RateLimitService
 	accountUsageService *service.AccountUsageService
 	accountTestService  *service.AccountTestService
@@ -42,6 +43,7 @@ func NewAccountHandler(
 	adminService service.AdminService,
 	oauthService *service.OAuthService,
 	openaiOAuthService *service.OpenAIOAuthService,
+	geminiOAuthService *service.GeminiOAuthService,
 	rateLimitService *service.RateLimitService,
 	accountUsageService *service.AccountUsageService,
 	accountTestService *service.AccountTestService,
@@ -52,6 +54,7 @@ func NewAccountHandler(
 		adminService:        adminService,
 		oauthService:        oauthService,
 		openaiOAuthService:  openaiOAuthService,
+		geminiOAuthService:  geminiOAuthService,
 		rateLimitService:    rateLimitService,
 		accountUsageService: accountUsageService,
 		accountTestService:  accountTestService,
@@ -345,6 +348,19 @@ func (h *AccountHandler) Refresh(c *gin.Context) {
 				newCredentials[k] = v
 			}
 		}
+	} else if account.Platform == model.PlatformGemini {
+		tokenInfo, err := h.geminiOAuthService.RefreshAccountToken(c.Request.Context(), account)
+		if err != nil {
+			response.InternalError(c, "Failed to refresh credentials: "+err.Error())
+			return
+		}
+
+		newCredentials = h.geminiOAuthService.BuildAccountCredentials(tokenInfo)
+		for k, v := range account.Credentials {
+			if _, exists := newCredentials[k]; !exists {
+				newCredentials[k] = v
+			}
+		}
 	} else {
 		// Use Anthropic/Claude OAuth service to refresh token
 		tokenInfo, err := h.oauthService.RefreshAccountToken(c.Request.Context(), account)