Add structured HTTP request logging and increase timeouts

- Replace chi's Logger middleware with structured slog-based logging
- Log request start (debug) and completion (info/warn/error by status)
- Include method, path, status, duration_ms, remote_addr in logs
- Increase request timeout from 8s to 30s for slow queries
- Add read/write/idle timeouts to HTTP server config
- Better server startup logging to confirm listening state

internal/server/middleware.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"net/http"
 	"sync"
 	"time"
@@ -301,3 +302,67 @@ func JSONValidationMiddleware(next http.Handler) http.Handler {
 		_ = json.NewEncoder(w).Encode(response)
 	})
 }
+
+// statusWriter wraps http.ResponseWriter to capture the status code
+type statusWriter struct {
+	http.ResponseWriter
+	statusCode int
+	written    bool
+}
+
+func (sw *statusWriter) WriteHeader(statusCode int) {
+	if !sw.written {
+		sw.statusCode = statusCode
+		sw.written = true
+	}
+	sw.ResponseWriter.WriteHeader(statusCode)
+}
+
+func (sw *statusWriter) Write(b []byte) (int, error) {
+	if !sw.written {
+		sw.statusCode = http.StatusOK
+		sw.written = true
+	}
+
+	return sw.ResponseWriter.Write(b)
+}
+
+// RequestLoggerMiddleware creates a structured logging middleware using slog.
+func RequestLoggerMiddleware(logger *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+
+			// Wrap response writer to capture status
+			sw := &statusWriter{ResponseWriter: w, statusCode: http.StatusOK}
+
+			// Log request start
+			logger.Debug("HTTP request started",
+				"method", r.Method,
+				"path", r.URL.Path,
+				"remote_addr", r.RemoteAddr,
+				"user_agent", r.UserAgent(),
+			)
+
+			// Serve the request
+			next.ServeHTTP(sw, r)
+
+			// Log request completion
+			duration := time.Since(start)
+			logLevel := slog.LevelInfo
+			if sw.statusCode >= http.StatusInternalServerError {
+				logLevel = slog.LevelError
+			} else if sw.statusCode >= http.StatusBadRequest {
+				logLevel = slog.LevelWarn
+			}
+
+			logger.Log(r.Context(), logLevel, "HTTP request completed",
+				"method", r.Method,
+				"path", r.URL.Path,
+				"status", sw.statusCode,
+				"duration_ms", duration.Milliseconds(),
+				"remote_addr", r.RemoteAddr,
+			)
+		})
+	}
+}