Merge branch 'main' into test-sora

backend/internal/pkg/antigravity/request_transformer.go

@@ -271,6 +271,21 @@ func filterOpenCodePrompt(text string) string {
 	return ""
 }
 
+// systemBlockFilterPrefixes 需要从 system 中过滤的文本前缀列表
+var systemBlockFilterPrefixes = []string{
+	"x-anthropic-billing-header",
+}
+
+// filterSystemBlockByPrefix 如果文本匹配过滤前缀，返回空字符串
+func filterSystemBlockByPrefix(text string) string {
+	for _, prefix := range systemBlockFilterPrefixes {
+		if strings.HasPrefix(text, prefix) {
+			return ""
+		}
+	}
+	return text
+}
+
 // buildSystemInstruction 构建 systemInstruction（与 Antigravity-Manager 保持一致）
 func buildSystemInstruction(system json.RawMessage, modelName string, opts TransformOptions, tools []ClaudeTool) *GeminiContent {
 	var parts []GeminiPart
@@ -287,8 +302,8 @@ func buildSystemInstruction(system json.RawMessage, modelName string, opts Trans
 				if strings.Contains(sysStr, "You are Antigravity") {
 					userHasAntigravityIdentity = true
 				}
-				// 过滤 OpenCode 默认提示词
-				filtered := filterOpenCodePrompt(sysStr)
+				// 过滤 OpenCode 默认提示词和黑名单前缀
+				filtered := filterSystemBlockByPrefix(filterOpenCodePrompt(sysStr))
 				if filtered != "" {
 					userSystemParts = append(userSystemParts, GeminiPart{Text: filtered})
 				}
@@ -302,8 +317,8 @@ func buildSystemInstruction(system json.RawMessage, modelName string, opts Trans
 						if strings.Contains(block.Text, "You are Antigravity") {
 							userHasAntigravityIdentity = true
 						}
-						// 过滤 OpenCode 默认提示词
-						filtered := filterOpenCodePrompt(block.Text)
+						// 过滤 OpenCode 默认提示词和黑名单前缀
+						filtered := filterSystemBlockByPrefix(filterOpenCodePrompt(block.Text))
 						if filtered != "" {
 							userSystemParts = append(userSystemParts, GeminiPart{Text: filtered})
 						}

backend/internal/pkg/ctxkey/ctxkey.go

@@ -28,4 +28,8 @@ const (
 	// IsMaxTokensOneHaikuRequest 标识当前请求是否为 max_tokens=1 + haiku 模型的探测请求
 	// 用于 ClaudeCodeOnly 验证绕过（绕过 system prompt 检查，但仍需验证 User-Agent）
 	IsMaxTokensOneHaikuRequest Key = "ctx_is_max_tokens_one_haiku"
+
+	// SingleAccountRetry 标识当前请求处于单账号 503 退避重试模式。
+	// 在此模式下，Service 层的模型限流预检查将等待限流过期而非直接切换账号。
+	SingleAccountRetry Key = "ctx_single_account_retry"
 )