Add devcontainer support for production-parity debugging

Dockerfile

@@ -64,7 +64,7 @@ WORKDIR /app
 # Don't run app as root
 RUN <<EOT
 groupadd -r app -g 10003
-useradd -r -d /app -u 10003 -s /sbin/nologin -g app -N app
+useradd -r -d /app -u 10003 -s /bin/bash -g app -N app
 EOT
 
 # Runtime dependencies
@@ -73,7 +73,7 @@ apt-get update -qy
 apt-get install -qyy \
     -o APT::Install-Recommends=false \
     -o APT::Install-Suggests=false \
-    xvfb curl
+    xvfb curl direnv
 apt-get clean
 rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 EOT
@@ -88,6 +88,8 @@ COPY --chown=app:app --chmod=700 /scripts/deploy.sh /deploy.sh
 
 ENTRYPOINT ["/entrypoint.sh"]
 
+RUN mkdir -p /app/.cursor-server && chown app:app /app /app/.cursor-server
+
 USER app
 
 EXPOSE 8000