refactor(server): migrate to zerolog, add request logging middleware

internal/server/server.go

@@ -3,15 +3,16 @@ package server
 import (
 	"context"
 	"fmt"
-	"log"
 	"net/http"
 	"strings"
 	"sync/atomic"
 
 	"github.com/gin-gonic/gin"
+	"github.com/rs/zerolog/log"
 
 	"github.com/fujin/anthropic-proxy/internal/auth"
 	"github.com/fujin/anthropic-proxy/internal/config"
+	"github.com/fujin/anthropic-proxy/internal/logging"
 	"github.com/fujin/anthropic-proxy/internal/proxy"
 )
 
@@ -37,6 +38,7 @@ func New(cfg *config.Config, pool *auth.Pool, profile *proxy.SniffedProfile) *Se
 	engine.Use(gin.Recovery())
 	engine.Use(corsMiddleware())
 	engine.Use(s.authMiddleware())
+	engine.Use(logging.GinRequestLogger())
 
 	handler := proxy.HandleMessages(pool, profile, func() *proxy.Sanitizer {
 		return s.sanitizer.Load()
@@ -50,7 +52,7 @@ func New(cfg *config.Config, pool *auth.Pool, profile *proxy.SniffedProfile) *Se
 		c.JSON(http.StatusOK, gin.H{"status": "ok"})
 	})
 	engine.NoRoute(func(c *gin.Context) {
-		log.Printf("unmatched route: %s %s", c.Request.Method, c.Request.URL.Path)
+		log.Warn().Str("method", c.Request.Method).Str("path", c.Request.URL.Path).Msg("unmatched route")
 		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
 	})
 
@@ -85,8 +87,7 @@ func (s *Server) handleReload() gin.HandlerFunc {
 		keys := makeKeySet(cfg.APIKeys)
 		s.apiKeys.Store(&keys)
 
-		log.Printf("config reloaded: %d tool renames, %d system rules, %d body rules, %d api keys",
-			len(cfg.Sanitize.Tools), len(cfg.Sanitize.System), len(cfg.Sanitize.Body), len(cfg.APIKeys))
+		log.Info().Int("tool_renames", len(cfg.Sanitize.Tools)).Int("system_rules", len(cfg.Sanitize.System)).Int("body_rules", len(cfg.Sanitize.Body)).Int("api_keys", len(cfg.APIKeys)).Msg("config reloaded")
 
 		c.JSON(http.StatusOK, gin.H{
 			"status":       "reloaded",