change: switch to uv-based Docker image for faster startup (#1419)

## Internal
### Updates & Improvements
- Speed up start up speeds with `--compile-bytecode` in `uv sync`. 
- Use `ghcr.io/astral-sh/uv:python3.11-trixie` image instead of
`python:3.11.6-bookworm`.
- Add `UV_FROZEN=1` and `UV_NO_DEV=1` to simplify docker run commands.

Author: ekassos

.dockerignore

@@ -33,3 +33,4 @@ docker.env
 __pycache__/
 .mypy_cache/
 saml/**/certs/*
+web/

Dockerfile.srv

@@ -1,9 +1,9 @@
 # Set up image based on uv / Python3.11
 
-FROM python:3.11.6-bookworm
+FROM ghcr.io/astral-sh/uv:0.10.4-python3.11-trixie
 
 RUN apt-get update \
-    && apt-get install -y ca-certificates ffmpeg \
+    && apt-get install -y ca-certificates ffmpeg --no-install-recommends \
     && update-ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
@@ -12,28 +12,29 @@ ARG SENTRY_RELEASE=""
 ENV PYTHONFAULTHANDLER=1 \
       PYTHONUNBUFFERED=1 \
       PYTHONHASHSEED=random \
-      PIP_NO_CACHE_DIR=off \
-      PIP_DISABLE_PIP_VERSION_CHECK=on \
-      PIP_DEFAULT_TIMEOUT=100 \
-      UV_SYSTEM_PYTHON=true \
+      NO_COLOR=1 \
+      UV_COMPILE_BYTECODE=1 \
+      UV_NO_DEV=1 \
       PATH="/code/.venv/bin:$PATH" \
       SENTRY_RELEASE=$SENTRY_RELEASE
 
-# Set up uv
-RUN pip install uv==0.10.4
-
 WORKDIR /code
 
+# Create runtime user early so COPY --chown can resolve app:app.
+RUN useradd --create-home --uid 10001 app
+
 # Copy dependency manifests
 COPY uv.lock pyproject.toml /code/
 
 # Install dependencies
-RUN uv sync --no-dev --locked --color never
+RUN uv sync --locked --color never
+RUN chown -R app:app /code/.venv
 
-COPY . /code
+# Disable uv's sync lockfile checking,
+# since we won't be modifying dependencies in the container.
+ENV UV_NO_SYNC=1
 
-RUN useradd --create-home --uid 10001 app \
-        && chown -R app:app /code
+COPY --chown=app:app . /code
 USER app
 
 CMD ["fastapi", "run", "pingpong", "--host", "0.0.0.0", "--port", "8000", "--workers", "4"]