Add Capacitor Android packaging (APK) for Cafe Bazaar / Myket

- Next static export (output: export) wrapped by Capacitor; appId
  com.bargevasat.app, appName «برگ وسط»
- android/ native project + @capacitor/app; hardware back handled by
  CapacitorBack (back a screen, exit at home)
- npm scripts (cap:sync, android:open, android:apk), ANDROID.md
- Gradle Maven-mirror init-script template (dl.google.com/Maven Central are
  blocked in Iran — same reason NuGet is mirrored)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

capacitor.config.ts

@@ -0,0 +1,13 @@
+import type { CapacitorConfig } from "@capacitor/cli";
+
+const config: CapacitorConfig = {
+  appId: "com.bargevasat.app",
+  appName: "برگ وسط",
+  webDir: "out",
+  backgroundColor: "#060c1f",
+  android: {
+    backgroundColor: "#060c1f",
+  },
+};
+
+export default config;