[Copilot]

/healthz is a high-frequency probe endpoint and was generating noisy access logs. This PR scopes access logging so health checks are omitted while preserving logs for all other routes.

• Logging middleware behavior

  • Updated LoggingMiddleware to skip log emission when r.URL.Path == "/healthz".
  • Kept request handling flow unchanged; only log side-effect is filtered.

• Targeted regression coverage

  • Added middleware tests to lock behavior:
    • /healthz requests do not produce access-log entries.
    • non-health endpoints (e.g. /v1/models) still produce access-log entries.

• Behavioral delta (code snippet)

func LoggingMiddleware(g *Gateway, next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/healthz" {
			logEntry := fmt.Sprintf("%s %s from %s", r.Method, r.URL.Path, r.RemoteAddr)
			g.logInfo("%s", logEntry)
		}
		next.ServeHTTP(w, r)
	})
}

• Fixes Exclude /healthz endpoint from access logs #6