fix: Antigravity project_id 获取优化

- API URL 改为只使用 prod 端点
- 刷新 token 时每次调用 LoadCodeAssist 更新 project_id
- 移除随机生成 project_id 的兜底逻辑

backend/internal/pkg/antigravity/oauth.go

@@ -42,11 +42,8 @@ const (
 	URLAvailabilityTTL = 5 * time.Minute
 )
 
-// BaseURLs 定义 Antigravity API 端点，按优先级排序
-// fallback 顺序: sandbox → daily → prod
+// BaseURLs 定义 Antigravity API 端点
 var BaseURLs = []string{
-	"https://daily-cloudcode-pa.sandbox.googleapis.com", // sandbox
-	"https://daily-cloudcode-pa.googleapis.com",         // daily
 	"https://cloudcode-pa.googleapis.com", // prod
 }
 
@@ -240,24 +237,3 @@ func BuildAuthorizationURL(state, codeChallenge string) string {
 
 	return fmt.Sprintf("%s?%s", AuthorizeURL, params.Encode())
 }
-
-// GenerateMockProjectID 生成随机 project_id（当 API 不返回时使用）
-// 格式：{形容词}-{名词}-{5位随机字符}
-func GenerateMockProjectID() string {
-	adjectives := []string{"useful", "bright", "swift", "calm", "bold"}
-	nouns := []string{"fuze", "wave", "spark", "flow", "core"}
-
-	randBytes, _ := GenerateRandomBytes(7)
-
-	adj := adjectives[int(randBytes[0])%len(adjectives)]
-	noun := nouns[int(randBytes[1])%len(nouns)]
-
-	// 生成 5 位随机字符（a-z0-9）
-	const charset = "abcdefghijklmnopqrstuvwxyz0123456789"
-	suffix := make([]byte, 5)
-	for i := 0; i < 5; i++ {
-		suffix[i] = charset[int(randBytes[i+2])%len(charset)]
-	}
-
-	return fmt.Sprintf("%s-%s-%s", adj, noun, string(suffix))
-}

backend/internal/service/antigravity_oauth_service.go

@@ -149,12 +149,6 @@ func (s *AntigravityOAuthService) ExchangeCode(ctx context.Context, input *Antig
 		result.ProjectID = loadResp.CloudAICompanionProject
 	}
 
-	// 兜底：随机生成 project_id
-	if result.ProjectID == "" {
-		result.ProjectID = antigravity.GenerateMockProjectID()
-		fmt.Printf("[AntigravityOAuth] 使用随机生成的 project_id: %s\n", result.ProjectID)
-	}
-
 	return result, nil
 }
 
@@ -236,14 +230,23 @@ func (s *AntigravityOAuthService) RefreshAccountToken(ctx context.Context, accou
 		return nil, err
 	}
 
-	// 保留原有的 project_id 和 email
+	// 保留原有的 email
+	existingEmail := strings.TrimSpace(account.GetCredential("email"))
+	if existingEmail != "" {
+		tokenInfo.Email = existingEmail
+	}
+
+	// 每次刷新都调用 LoadCodeAssist 更新 project_id
+	client := antigravity.NewClient(proxyURL)
+	loadResp, _, err := client.LoadCodeAssist(ctx, tokenInfo.AccessToken)
+	if err != nil {
+		// 失败时保留原有的 project_id
 		existingProjectID := strings.TrimSpace(account.GetCredential("project_id"))
 		if existingProjectID != "" {
 			tokenInfo.ProjectID = existingProjectID
 		}
-	existingEmail := strings.TrimSpace(account.GetCredential("email"))
-	if existingEmail != "" {
-		tokenInfo.Email = existingEmail
+	} else if loadResp != nil && loadResp.CloudAICompanionProject != "" {
+		tokenInfo.ProjectID = loadResp.CloudAICompanionProject
 	}
 
 	return tokenInfo, nil

backend/internal/service/antigravity_quota_fetcher.go

@@ -31,11 +31,6 @@ func (f *AntigravityQuotaFetcher) FetchQuota(ctx context.Context, account *Accou
 	accessToken := account.GetCredential("access_token")
 	projectID := account.GetCredential("project_id")
 
-	// 如果没有 project_id，生成一个随机的
-	if projectID == "" {
-		projectID = antigravity.GenerateMockProjectID()
-	}
-
 	client := antigravity.NewClient(proxyURL)
 
 	// 调用 API 获取配额