Function tf_cleanup_cache_sentinel

tests/test_main.c:188–192

static char tf_home_sentinel[512];

static void tf_cleanup_cache_sentinel(void) {
    if (tf_home_sentinel[0]) {
        th_rmtree(tf_home_sentinel);
    }
}

/* Client home overrides the CLI honours BEFORE $HOME, so redirecting HOME alone
 * does not isolate them: cbm_codex_config_dir() and its siblings return the