Add Docker entrypoint and cleanup gitignore

- Add entrypoint.sh for automated app initialization (composer, npm, migrations, cache)
- Update Dockerfile: run entrypoint as root, php-fpm workers still run as appuser
- Update .gitignore: exclude storage/logs, storage/framework, bootstrap/cache, public/build
- Remove generated/cached files from git tracking

.gitignore

@@ -2,8 +2,12 @@
 /node_modules/
 /.env
 /storage/*.key
+/storage/logs/
+/storage/framework/
+/bootstrap/cache/
 /public/hot
 /public/storage
+/public/build/
 /.phpunit.result.cache
 /.idea/
 /.vscode/