Add OAuth2/OIDC per-user Gitea authentication

Introduce a GiteaOAuthValidator for JWT and userinfo validation and
fallbacks, add /oauth/token proxy, and thread per-user tokens through
the
request context and automation paths. Update config and .env.example for
OAuth-first mode, add OpenAPI, extensive unit/integration tests,
GitHub/Gitea CI workflows, docs, and lint/test enforcement (>=80% cov).

docker/Dockerfile

@@ -5,6 +5,7 @@ FROM python:3.12-slim AS builder
 
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
+ENV PIP_DISABLE_PIP_VERSION_CHECK=1
 
 WORKDIR /app
 
@@ -20,6 +21,9 @@ FROM python:3.12-slim
 
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
+ENV PIP_DISABLE_PIP_VERSION_CHECK=1
+ENV NODE_ENV=production
+ENV ENVIRONMENT=production
 ENV PATH=/home/aegis/.local/bin:$PATH
 ENV PYTHONPATH=/app/src:$PYTHONPATH