feat(deploy): finalize MVP deployment and file transfer approach

Dockerfile

@@ -1,6 +1,8 @@
 FROM python:3.11-slim AS base
 
 WORKDIR /app
+RUN useradd -u 1000 -m appuser
+USER appuser
 
 ENV PYTHONUNBUFFERED=1
 ENV PYTHONPATH=/app
@@ -20,25 +22,25 @@ RUN uv sync --no-dev --no-install-project --frozen
 
 FROM base AS development
 
+COPY . .
+RUN uv sync --no-dev --frozen
+
 # Local fullstack/dev builds can override the SDK with a checked-out agent_api
 # build context, matching platform-agent's development Dockerfile pattern.
 COPY --from=agent_api . /agent_api/
 RUN python -m pip install --no-cache-dir --ignore-requires-python -e /agent_api/
 
-COPY . .
-RUN uv sync --no-dev --frozen
-
 CMD ["python", "-m", "adapter.matrix.bot"]
 
 FROM base AS production
 
+COPY . .
+RUN uv sync --no-dev --frozen
+
 # Production builds follow the platform-agent pattern: install the API SDK from
 # the platform Git repository instead of relying on local external/ clones.
 ARG LAMBDA_AGENT_API_REF=master
 RUN python -m pip install --no-cache-dir --ignore-requires-python \
     "git+https://git.lambda.coredump.ru/platform/agent_api.git@${LAMBDA_AGENT_API_REF}"
 
-COPY . .
-RUN uv sync --no-dev --frozen
-
 CMD ["python", "-m", "adapter.matrix.bot"]