fix(launcher): 字库启动竞态两连修 — ①卡就绪(热插拔轮询)后重扫字库 presets（开机早扫时卡未挂载只剩默认项,App 大字库声明落空→豆腐块）②扫描根目录不可读且仅默认项时不写 index（修开机覆盖掉卡上18条索引）

launcher b33da20a→9ae64777; test_font_tier PASS

patch_v2/meow_launcherd/main_menu.c

@@ -898,6 +898,7 @@ static void run_menu(struct app apps[MAX_APPS], int napps, int state,
                 int was_nocard = (state == 1);
                 if (!mfont_ready && meow_font_ensure()) { dirty = 1; logmsg("hotplug: font loaded late"); }
                 if (mfont_ready) meow_font_reload_multifont();   /* M2.5x：卡挂载后重配多字体（此前无全局可配） */
+                meow_font_scan_presets();   /* M2.82+：卡就绪后重扫字库（启动时卡未挂载会只有默认项） */
                 if (was_nocard || state != 0 || napps == 0) {
                     struct app fresh[MAX_APPS];
                     int fn = scan_apps(fresh);