feat(antigravity): 从 LoadCodeAssist 复用 TierInfo 提取 plan_type

复用已有 GetTier() 返回的 tier ID（free-tier / g1-pro-tier /
g1-ultra-tier），通过 TierIDToPlanType 映射为 Free / Pro / Ultra，
在 loadProjectIDWithRetry 中顺带提取并写入 credentials.plan_type；
前端增加 Abnormal 异常套餐红色标记。

Made-with: Cursor

backend/internal/pkg/antigravity/client.go

@@ -78,7 +78,9 @@ type UserInfo struct {
 // LoadCodeAssistRequest loadCodeAssist 请求
 type LoadCodeAssistRequest struct {
 	Metadata struct {
-		IDEType string `json:"ideType"`
+		IDEType    string `json:"ideType"`
+		IDEVersion string `json:"ideVersion"`
+		IDEName    string `json:"ideName"`
 	} `json:"metadata"`
 }
 
@@ -223,6 +225,23 @@ func (r *LoadCodeAssistResponse) GetAvailableCredits() []AvailableCredit {
 	return r.PaidTier.AvailableCredits
 }
 
+// TierIDToPlanType 将 tier ID 映射为用户可见的套餐名。
+func TierIDToPlanType(tierID string) string {
+	switch strings.ToLower(strings.TrimSpace(tierID)) {
+	case "free-tier":
+		return "Free"
+	case "g1-pro-tier":
+		return "Pro"
+	case "g1-ultra-tier":
+		return "Ultra"
+	default:
+		if tierID == "" {
+			return "Free"
+		}
+		return tierID
+	}
+}
+
 // Client Antigravity API 客户端
 type Client struct {
 	httpClient *http.Client
@@ -421,6 +440,8 @@ func (c *Client) GetUserInfo(ctx context.Context, accessToken string) (*UserInfo
 func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadCodeAssistResponse, map[string]any, error) {
 	reqBody := LoadCodeAssistRequest{}
 	reqBody.Metadata.IDEType = "ANTIGRAVITY"
+	reqBody.Metadata.IDEVersion = "1.20.6"
+	reqBody.Metadata.IDEName = "antigravity"
 
 	bodyBytes, err := json.Marshal(reqBody)
 	if err != nil {

backend/internal/pkg/antigravity/client_test.go

@@ -250,6 +250,27 @@ func TestGetTier_两者都为nil(t *testing.T) {
 	}
 }
 
+func TestTierIDToPlanType(t *testing.T) {
+	tests := []struct {
+		tierID string
+		want   string
+	}{
+		{"free-tier", "Free"},
+		{"g1-pro-tier", "Pro"},
+		{"g1-ultra-tier", "Ultra"},
+		{"FREE-TIER", "Free"},
+		{"", "Free"},
+		{"unknown-tier", "unknown-tier"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.tierID, func(t *testing.T) {
+			if got := TierIDToPlanType(tt.tierID); got != tt.want {
+				t.Errorf("TierIDToPlanType(%q) = %q, want %q", tt.tierID, got, tt.want)
+			}
+		})
+	}
+}
+
 // ---------------------------------------------------------------------------
 // NewClient
 // ---------------------------------------------------------------------------
@@ -800,6 +821,12 @@ type redirectRoundTripper struct {
 	transport http.RoundTripper
 }
 
+type roundTripperFunc func(*http.Request) (*http.Response, error)
+
+func (f roundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req)
+}
+
 func (rt *redirectRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
 	originalURL := req.URL.String()
 	for prefix, target := range rt.redirects {
@@ -1271,6 +1298,12 @@ func TestClient_LoadCodeAssist_Success_RealCall(t *testing.T) {
 		if reqBody.Metadata.IDEType != "ANTIGRAVITY" {
 			t.Errorf("IDEType 不匹配: got %s, want ANTIGRAVITY", reqBody.Metadata.IDEType)
 		}
+		if strings.TrimSpace(reqBody.Metadata.IDEVersion) == "" {
+			t.Errorf("IDEVersion 不应为空")
+		}
+		if reqBody.Metadata.IDEName != "antigravity" {
+			t.Errorf("IDEName 不匹配: got %s, want antigravity", reqBody.Metadata.IDEName)
+		}
 
 		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusOK)