fix: first-boot container creation, remote input relay, ISO packages

Critical first-boot fixes (root cause: ALL 25 containers failed on install):
- Fix image-versions.sh sourcing: multi-path fallback for /opt/archipelago/scripts/
- Fix --add-host host-gateway: resolve actual gateway IP (podman 4.3 compat)
- Fix disk size detection: check /var/lib/archipelago not / (was forcing prune on 428GB disk)
- Fix Bitcoin health check: expand $RPC vars at creation, not inside container
- Add --network-alias to all containers (aardvark-dns reliability)
- Add --network-alias to backend RPC install handler

ISO build:
- Add apache2-utils for htpasswd (Fedimint gateway password hashing)

Remote input:
- Add broadcast relay channel for companion app → browser input forwarding
- Add /ws/remote-relay WebSocket endpoint
- Android: NES controller improvements, server connect flow updates

Container images:
- Fix lnd-ui Dockerfile: listen on 8080, run as root user (rootless compat)
- Fix bitcoin-ui, electrs-ui Dockerfiles: root user for rootless podman

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

image-recipe/build-auto-installer-iso.sh

@@ -301,6 +301,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     plymouth-themes \
     zstd \
     python3 \
+    apache2-utils \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*