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/server.go

@@ -57,16 +57,27 @@ func (s *Server) Start() error {
 		port = "8080"
 	}
 
-	const readHeaderTimeout = 40 * time.Second
+	const (
+		readHeaderTimeout = 40 * time.Second
+		readTimeout       = 60 * time.Second
+		writeTimeout      = 60 * time.Second
+		idleTimeout       = 120 * time.Second
+	)
+
 	s.srv = &http.Server{
 		Addr:              ":" + port,
 		Handler:           s.router,
 		ReadHeaderTimeout: readHeaderTimeout,
+		ReadTimeout:       readTimeout,
+		WriteTimeout:      writeTimeout,
+		IdleTimeout:       idleTimeout,
 	}
 
-	s.logger.Info("Starting HTTP server", "port", port)
+	s.logger.Info("Starting HTTP server", "port", port, "addr", s.srv.Addr)
 
+	// Start in goroutine but log when actually listening
 	go func() {
+		s.logger.Info("HTTP server listening", "addr", s.srv.Addr)
 		if err := s.srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
 			s.logger.Error("HTTP server error", "error", err)
 		}