Simplify release workflow: remove signing, fix deprecated action

.github/workflows/release.yml

@@ -27,45 +27,22 @@ jobs:
         run: echo '${{ secrets.GOOGLE_JSON }}' | base64 --decode > app/google-services.json
 
       - name: Validate Gradle wrapper
-        uses: gradle/wrapper-validation-action@v3
+        uses: gradle/actions/wrapper-validation@v4
 
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew
 
       - name: Build release APK
         run: ./gradlew assembleRelease
 
-      - name: Sign APK
-        if: ${{ secrets.KEYSTORE_BASE64 != '' }}
-        uses: r0adkll/sign-android-release@v1
-        id: sign_app
-        with:
-          releaseDirectory: app/build/outputs/apk/release
-          signingKeyBase64: ${{ secrets.KEYSTORE_BASE64 }}
-          alias: ${{ secrets.KEY_ALIAS }}
-          keyStorePassword: ${{ secrets.KEYSTORE_PASSWORD }}
-          keyPassword: ${{ secrets.KEY_PASSWORD }}
-
-      - name: Upload signed APK to GitHub Releases
-        if: ${{ secrets.KEYSTORE_BASE64 != '' }}
-        uses: softprops/action-gh-release@v2
-        with:
-          files: ${{ steps.sign_app.outputs.signedReleaseFile }}
-          generate_release_notes: true
-          draft: false
-          prerelease: false
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Upload unsigned APK to GitHub Releases (fallback)
-        if: ${{ secrets.KEYSTORE_BASE64 == '' }}
+      - name: Upload APK to GitHub Releases
         uses: softprops/action-gh-release@v2
         with:
           files: app/build/outputs/apk/release/app-release-unsigned.apk
           generate_release_notes: true
           draft: false
           prerelease: false
           body: |
-            > ⚠️ **Note:** This APK is unsigned. You may need to enable "Install from unknown sources" and sign it manually, or use the Play Store version instead.
+            > ⚠️ This APK is unsigned. Enable "Install from unknown sources" on your device to install it.
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}