refactor(runner): improve SAM2 container dev experience (#257)

This commit mounts the app folder in the SAM2 pipeline container so that
developers don't have to always rebuild the base container to get the
latest changes.

runner/docker/Dockerfile.segment_anything_2

@@ -3,4 +3,7 @@ FROM ${BASE_IMAGE}
 
 RUN pip install --no-cache-dir torch==2.3.1 torchvision==0.18.1 torchaudio==2.3.1 xformers==0.0.27 git+https://github.com/facebookresearch/sam2.git@0f6515ae853c40420ea8e3dd250f8031bbf03023#egg=sam-2
 
+# Copy app directory to avoid rebuilding the base image during development.
+COPY app /app
+
 CMD ["uvicorn", "app.main:app", "--log-config", "app/cfg/uvicorn_logging_config.json", "--host", "0.0.0.0", "--port", "8000"]