main:重构指标系统并切换为 Redis 方案

变更内容：
- 重构指标系统实现，支持基于 Redis 的多实例指标管理。
- 替换原有的 Pushgateway 和 Redis Exporter 方案。
- 更新 Prometheus 配置，适配新的指标抓取方式。
- 添加 Redis 指标相关配置和告警规则文件。
- 更新 Dockerfile 和 docker-compose 文件，移除多余服务，精简配置。
- 编写 `metrics_unified.py` 模块及单元测试。
- 修复部分代码中的冗余和格式问题。

src/functional_scaffold/main.py

@@ -3,14 +3,20 @@
 from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import Response
-from prometheus_client import generate_latest, CONTENT_TYPE_LATEST
 import logging
 import time
 
 from .api import router
 from .config import settings
 from .core.logging import setup_logging
-from .core.metrics import metrics_registry, request_counter, request_latency, in_progress_requests
+from .core.metrics_unified import (
+    get_metrics_manager,
+    incr,
+    observe,
+    gauge_incr,
+    gauge_decr,
+    export,
+)
 
 # 设置日志
 setup_logging(level=settings.log_level, format_type=settings.log_format)
@@ -57,7 +63,7 @@ async def track_metrics(request: Request, call_next):
     if request.url.path == "/metrics":
         return await call_next(request)
 
-    in_progress_requests.inc()
+    gauge_incr("http_requests_in_progress")
     start_time = time.time()
     status = "success"
 
@@ -72,16 +78,16 @@ async def track_metrics(request: Request, call_next):
         raise e
     finally:
         elapsed = time.time() - start_time
-        request_counter.labels(
-            method=request.method,
-            endpoint=request.url.path,
-            status=status
-        ).inc()
-        request_latency.labels(
-            method=request.method,
-            endpoint=request.url.path
-        ).observe(elapsed)
-        in_progress_requests.dec()
+        incr(
+            "http_requests_total",
+            {"method": request.method, "endpoint": request.url.path, "status": status},
+        )
+        observe(
+            "http_request_duration_seconds",
+            {"method": request.method, "endpoint": request.url.path},
+            elapsed,
+        )
+        gauge_decr("http_requests_in_progress")
 
 
 # 注册路由
@@ -105,8 +111,8 @@ async def metrics():
         return Response(content="Metrics disabled", status_code=404)
 
     return Response(
-        content=generate_latest(metrics_registry),
-        media_type=CONTENT_TYPE_LATEST,
+        content=export(),
+        media_type="text/plain; version=0.0.4; charset=utf-8",
     )
 
 
@@ -118,6 +124,14 @@ async def startup_event():
     logger.info(f"Environment: {settings.app_env}")
     logger.info(f"Metrics enabled: {settings.metrics_enabled}")
 
+    # 初始化指标管理器
+    if settings.metrics_enabled:
+        manager = get_metrics_manager()
+        if manager.is_available():
+            logger.info("Redis 指标收集已启用")
+        else:
+            logger.warning("Redis 不可用，指标将不会被收集")
+
 
 # 关闭事件
 @app.on_event("shutdown")