feat: sign Android APK and generate icons from logo.png or favicon.ico

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/generate-android-keystore.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+OUT="${1:-web2app-release.jks}"
+ALIAS="${2:-web2app}"
+
+echo "Generating keystore: ${OUT}"
+keytool -genkeypair -v \
+  -keystore "${OUT}" \
+  -alias "${ALIAS}" \
+  -keyalg RSA \
+  -keysize 2048 \
+  -validity 10000 \
+  -storepass "${ANDROID_KEYSTORE_PASSWORD:-changeit}" \
+  -keypass "${ANDROID_KEY_PASSWORD:-changeit}" \
+  -dname "CN=Web2App, OU=Mobile, O=Web2App, L=Local, ST=Local, C=CN"
+
+echo ""
+echo "Add these GitHub repository secrets:"
+echo "  ANDROID_KEYSTORE_BASE64=$(base64 -w 0 "${OUT}" 2>/dev/null || base64 -i "${OUT}")"
+echo "  ANDROID_KEYSTORE_PASSWORD=${ANDROID_KEYSTORE_PASSWORD:-changeit}"
+echo "  ANDROID_KEY_PASSWORD=${ANDROID_KEY_PASSWORD:-changeit}"
+echo "  ANDROID_KEY_ALIAS=${ALIAS}"