Add OAuth server implementation and Docker Compose configuration

- Introduced a new `compose.yaml` file to define the Docker service for the OAuth server.
- Created `oauth.py` to implement a single-user OAuth authorization server with PKCE, SQLite persistence, and token management.
- Added necessary database schema for OAuth clients, flows, codes, tokens, and login failures.
- Implemented login routes with CSRF protection and error handling.
- Updated `requirements.txt` to include dependencies for the OAuth server.

Dockerfile

@@ -0,0 +1,24 @@
+FROM python:3.12-slim
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PIP_DISABLE_PIP_VERSION_CHECK=1
+
+WORKDIR /app
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends ca-certificates \
+    && rm -rf /var/lib/apt/lists/* \
+    && useradd --system --uid 10001 --create-home --home-dir /home/app app \
+    && mkdir -p /data \
+    && chown app:app /data
+
+COPY requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY --chown=app:app app.py oauth.py ./
+
+USER 10001:10001
+EXPOSE 8000
+
+CMD ["sh", "-c", "umask 077 && exec uvicorn app:app --host 0.0.0.0 --port 8000 --proxy-headers --forwarded-allow-ips=*"]