// Thread-safe URL pattern matching using strtok_r
static int match_pattern(const char* pattern, const char* path, Request* req)
{
    if (!strchr(pattern, '{'))
        return strcmp(pattern, path) == 0;

    char pat_copy[256], path_copy[256];
    strncat(pat_copy, pattern, sizeof(pat_copy) - 1);
    strncat(path_copy, path, sizeof(path_copy) - 1);

    char *save1, *save2;
    char* p_seg    = strtok_r(pat_copy,  "/", &save1);
    char* path_seg = strtok_r(path_copy, "/", &save2);

    while (p_seg && path_seg) {
        if (p_seg[0] == '{') {
            // extract {id} → bind to request param
            request_set_param(req, param, path_seg);
        } else if (strcmp(p_seg, path_seg) != 0) {
            return 0;
        }
        p_seg    = strtok_r(NULL, "/", &save1);
        path_seg = strtok_r(NULL, "/", &save2);
    }
    return (p_seg == NULL && path_seg == NULL);
}