fix: CSRF race condition, UI containers, Tor ordering, seed layout

- session.rs: use OnceCell for remember_secret to prevent concurrent
  requests on first boot from generating different HMAC secrets, which
  caused CSRF token mismatch on every state-changing RPC call (app
  install, start, stop all failed with "CSRF token missing or invalid")

- install.rs: write lnd.conf with Bitcoin RPC credentials before LND
  container starts (prevents "bitcoin.mainnet must be specified" crash);
  inject Bitcoin RPC auth into bitcoin-ui nginx.conf; add proper error
  logging to UI container build/run steps; fix UI containers to use
  --network=host (they proxy to localhost backend/bitcoin RPC)

- Tor: remove After=tor.service from archipelago-tor-helper.path to
  break systemd ordering cycle that prevented Tor from starting on boot

- Seed screen: compact grid layout (2 cols mobile, 4 cols sm+) with
  tighter padding to fit kiosk displays without scrolling

- Dockerfiles: remove nonexistent assets/ COPY from bitcoin-ui, fix
  electrs-ui to COPY qrcode.js and EXPOSE 50002 (matches nginx.conf)

- image-versions.sh: add UI container image variables for registry

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/bitcoin-ui/Dockerfile

@@ -1,7 +1,6 @@
 FROM 80.71.235.15:3000/archipelago/nginx:1.27.4-alpine
 COPY index.html /usr/share/nginx/html/
 COPY 50x.html /usr/share/nginx/html/
-COPY assets/ /usr/share/nginx/html/assets/
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 EXPOSE 8334
 CMD ["nginx", "-g", "daemon off;"]

docker/electrs-ui/Dockerfile

@@ -1,7 +1,7 @@
 FROM 80.71.235.15:3000/archipelago/nginx:1.27.4-alpine
 COPY index.html /usr/share/nginx/html/
 COPY 50x.html /usr/share/nginx/html/
-COPY assets/ /usr/share/nginx/html/assets/
+COPY qrcode.js /usr/share/nginx/html/
 COPY nginx.conf /etc/nginx/conf.d/default.conf
-EXPOSE 80
+EXPOSE 50002
 CMD ["nginx", "-g", "daemon off;"]