chore(admin): stop tracking SPA build; add native product meta box

Remove assets/admin/build from version control (local build only going
forward). Add AKSRT_Product_Meta_Box so product price/stock/shipping/after-
sale fields can be edited on the native aksrt_product edit screen without
the SPA product drawer.

assets/admin/build/UsersVerify.css

@@ -1 +0,0 @@
-.aksrt-verify-drawer__section[data-v-84e367b4]{margin-top:20px}.aksrt-verify-drawer__title[data-v-84e367b4]{margin-bottom:10px;font-size:14px;font-weight:600;color:#1f2937}.aksrt-verify-drawer__timeline[data-v-84e367b4]{display:grid;gap:12px}.aksrt-verify-drawer__timeline-item[data-v-84e367b4]{padding:12px;border:1px solid #e5e7eb;border-radius:12px;background:#f8fafc}.aksrt-verify-drawer__timeline-head[data-v-84e367b4]{display:flex;justify-content:space-between;gap:12px;margin-bottom:6px}.aksrt-verify-drawer__timeline-item p[data-v-84e367b4]{margin:0 0 6px;color:#111827;white-space:pre-wrap}.aksrt-verify-drawer__timeline-item small[data-v-84e367b4]{color:#6b7280}.aksrt-verify-page__card[data-v-96c64f9f]{margin-top:16px}