feat(worker): 实现集群限流与自适应负载

保留平台模型 RPM、TPM 和并发策略语义，增加 PostgreSQL 集群级租约、饱和候选重选和多平台自动负载，避免突发任务固定等待首个平台。\n\n新增 Worker 实时负载采样、自适应 active/heavy 容量、心跳与管理端指标，并扩展本地 acceptance runner，覆盖三 Worker、同模型三平台 2/4/6 并发和 48 个带图视频突发任务。\n\n验证：go test ./...、go vet ./...、PostgreSQL 跨 Store 集成测试、gofmt、bash -n、ShellCheck 及本地集群 provider-burst 验收通过；48/48 成功，无越限、重复提交、重复计费、重复回调或终态资源泄漏。

apps/api/internal/acceptanceemulator/server.go

@@ -59,6 +59,7 @@ type Server struct {
 type Report struct {
 	GeminiRequests       int64            `json:"geminiRequests"`
 	GeminiInvalid        int64            `json:"geminiInvalid"`
+	GeminiInputImages    int64            `json:"geminiInputImages"`
 	GeminiInputBytes     int64            `json:"geminiInputBytes"`
 	GeminiOutputBytes    int64            `json:"geminiOutputBytes"`
 	VideoSubmissions     int64            `json:"videoSubmissions"`
@@ -163,7 +164,7 @@ func (s *Server) geminiGenerateContent(w http.ResponseWriter, r *http.Request) {
 		writeProtocolError(w, http.StatusBadRequest, err.Error())
 		return
 	}
-	inputBytes, err := validateGeminiImageRequest(body)
+	inputBytes, inputImages, err := validateGeminiImageRequest(body)
 	if err != nil {
 		s.recordGeminiInvalid()
 		writeProtocolError(w, http.StatusBadRequest, err.Error())
@@ -180,6 +181,7 @@ func (s *Server) geminiGenerateContent(w http.ResponseWriter, r *http.Request) {
 		s.geminiIdempotency[idempotencyKey] = struct{}{}
 	}
 	s.report.GeminiRequests++
+	s.report.GeminiInputImages += int64(inputImages)
 	s.report.GeminiInputBytes += int64(inputBytes)
 	s.report.GeminiOutputBytes += int64(outputBytes)
 	s.mu.Unlock()
@@ -533,7 +535,7 @@ func decodeImageDataURL(raw string) ([]byte, error) {
 	return payload, nil
 }
 
-func validateGeminiImageRequest(body map[string]any) (int, error) {
+func validateGeminiImageRequest(body map[string]any) (int, int, error) {
 	generationConfig, _ := body["generationConfig"].(map[string]any)
 	modalities, _ := generationConfig["responseModalities"].([]any)
 	hasImageModality := false
@@ -543,9 +545,10 @@ func validateGeminiImageRequest(body map[string]any) (int, error) {
 		}
 	}
 	if !hasImageModality {
-		return 0, errors.New("generationConfig.responseModalities must contain IMAGE")
+		return 0, 0, errors.New("generationConfig.responseModalities must contain IMAGE")
 	}
 	total := 0
+	images := 0
 	contents, _ := body["contents"].([]any)
 	for _, rawContent := range contents {
 		content, _ := rawContent.(map[string]any)
@@ -558,22 +561,41 @@ func validateGeminiImageRequest(body map[string]any) (int, error) {
 			}
 			encoded := strings.TrimSpace(stringValue(inline["data"]))
 			if encoded == "" {
+				fileData, _ := part["fileData"].(map[string]any)
+				if fileData == nil {
+					fileData, _ = part["file_data"].(map[string]any)
+				}
+				fileURI := strings.TrimSpace(stringValue(fileData["fileUri"]))
+				if fileURI == "" {
+					fileURI = strings.TrimSpace(stringValue(fileData["file_uri"]))
+				}
+				if fileURI == "" {
+					fileURI = strings.TrimSpace(stringValue(fileData["uri"]))
+				}
+				if fileURI == "" {
+					continue
+				}
+				if !strings.HasPrefix(fileURI, "http://") && !strings.HasPrefix(fileURI, "https://") {
+					return 0, 0, errors.New("Gemini fileData URI must use HTTP or HTTPS")
+				}
+				images++
 				continue
 			}
 			decoded, err := base64.StdEncoding.DecodeString(encoded)
 			if err != nil {
-				return 0, fmt.Errorf("Gemini inlineData is not valid Base64: %w", err)
+				return 0, 0, fmt.Errorf("Gemini inlineData is not valid Base64: %w", err)
 			}
 			if len(decoded) == 0 {
-				return 0, errors.New("Gemini inlineData is empty")
+				return 0, 0, errors.New("Gemini inlineData is empty")
 			}
 			total += len(decoded)
+			images++
 		}
 	}
-	if total == 0 {
-		return 0, errors.New("Gemini request has no inlineData image")
+	if images == 0 {
+		return 0, 0, errors.New("Gemini request has no inlineData or fileData image")
 	}
-	return total, nil
+	return total, images, nil
 }
 
 func (s *Server) recordGeminiInvalid() {