feat(lyra)!: 添加结构化日志与请求追踪

- 配置 slog JSON 输出和日志级别
- 添加请求 ID、访问日志及上下文日志工具
- 拆分启动初始化并统一启动失败处理

BREAKING CHANGE: 配置文件必须提供 log.level，缺失或非法将导致启动失败

go/projects/lyra/internal/middleware/accessLog.go

@@ -0,0 +1,30 @@
+package middleware
+
+import (
+	"lyra/internal/util"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+func AccessLogMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		start := time.Now()
+
+		c.Next()
+
+		ctx := c.Request.Context()
+
+		util.Logger(ctx).InfoContext(
+			ctx,
+			"http request",
+			"method", c.Request.Method,
+			"path", c.Request.URL.Path,
+			"status", c.Writer.Status(),
+			"latency_ms", time.Since(start).Milliseconds(),
+			"client_ip", c.ClientIP(),
+			"user_agent", c.Request.UserAgent(),
+			"response_size", c.Writer.Size(),
+		)
+	}
+}