Update Dockerfile

Dockerfile

@@ -5,9 +5,13 @@ WORKDIR /build
 COPY requirements.txt .
 RUN pip install --prefix=/install -r requirements.txt
 
-COPY app.py .
-RUN python -m compileall -b -f app.py          # → app.pyc
-RUN tar -czf /build/app.tgz app.pyc            # bundle
+COPY app.py telegram_preview.py ./
+
+# compile both files
+RUN python -m compileall -b -f app.py telegram_preview.py          # → app.pyc
+
+# bundle both .pyc files together
+RUN tar -czf /build/app.tgz app.pyc telegram_preview.pyc            # bundle
 
 ################ runtime ################
 FROM python:3.9-slim
@@ -28,5 +32,5 @@ ENTRYPOINT ["bash", "-c", "\
   tar -xzf /tmp/runner/app.tgz -C /tmp/runner; \
   python /tmp/runner/app.pyc & pid=$!; \
   sleep 2; \
-  rm -f /tmp/runner/app.pyc /tmp/runner/app.tgz; \
+  rm -f /tmp/runner/app.pyc /tmp/runner/telegram_preview.pyc /tmp/runner/app.tgz; \
   wait $pid"]