build(admin): track the SPA build output so git deploys carry it

assets/admin/build was gitignored, so servers deployed by git pull kept
running a stale admin bundle — the icon picker integration in the tabbar
and floating-button settings pages never reached them. Track the build
directory (rebuild with: cd assets/admin && npm run build) and commit the
current bundle containing the universal icon picker.

assets/admin/build/PageHeader.css

@@ -0,0 +1 @@
+.aksrt-page-header[data-v-9e7de2bf]{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:20px;flex-wrap:wrap}.aksrt-page-header__main[data-v-9e7de2bf]{flex:1 1 auto;min-width:0}.aksrt-page-header__title[data-v-9e7de2bf]{margin:0 0 6px;color:var(--aksrt-color-text);font-size:22px;font-weight:700;letter-spacing:-.02em;line-height:1.3}.aksrt-page-header__desc[data-v-9e7de2bf]{margin:0;color:var(--aksrt-color-muted);font-size:13px;line-height:1.65}.aksrt-page-header__actions[data-v-9e7de2bf]{flex:0 0 auto;display:flex;align-items:center;gap:8px}@media(max-width:768px){.aksrt-page-header[data-v-9e7de2bf]{margin-bottom:14px;gap:10px}.aksrt-page-header__title[data-v-9e7de2bf]{font-size:18px}.aksrt-page-header__desc[data-v-9e7de2bf]{font-size:12px}.aksrt-page-header__actions[data-v-9e7de2bf]{width:100%}}