feat(scripts): one-command APK build + upload to the fixed Gitea release

`npm run publish-apk` builds the APK (assembleDebug by default — the release
build type is unsigned) and uploads it to the apk-latest Gitea release,
replacing the old .apk asset, so the web download button always serves the
latest build. Config via env or a gitignored scripts/.env.release
(GITEA_URL/REPO/TOKEN, APK_GRADLE_TASK). Release title tracks versionName.

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

.gitignore

@@ -2,3 +2,4 @@
 *.log
 node_modules/
 dist/
+scripts/.env.release