feat: migrate all container images to Archipelago app registry

All container image references now pull from 80.71.235.15:3000/archipelago/
instead of Docker Hub and ghcr.io. image-versions.sh is the single source
of truth; all scripts use $*_IMAGE variables instead of hardcoded refs.

Files updated:
- scripts/image-versions.sh: central ARCHY_REGISTRY variable
- core/*/config.rs: registry whitelist includes app registry
- core/*/stacks.rs: Immich + Penpot stack images
- scripts/{first-boot,deploy-to-target,container-specs}.sh: use variables
- docker/*/Dockerfile: nginx base image from registry
- image-recipe/: ISO build, podman config, menu script
- scripts/{container-doctor,deploy-bitcoin-knots,fix-indeedhub,validate-app-manifest}.sh

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

docker/bitcoin-ui/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/nginx:alpine
+FROM 80.71.235.15:3000/archipelago/nginx:1.29.6-alpine
 COPY index.html /usr/share/nginx/html/
 COPY 50x.html /usr/share/nginx/html/
 COPY assets/ /usr/share/nginx/html/assets/

docker/electrs-ui/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/nginx:alpine
+FROM 80.71.235.15:3000/archipelago/nginx:1.29.6-alpine
 COPY index.html /usr/share/nginx/html/
 COPY 50x.html /usr/share/nginx/html/
 COPY assets/ /usr/share/nginx/html/assets/

docker/lnd-ui/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/nginx:alpine
+FROM 80.71.235.15:3000/archipelago/nginx:1.29.6-alpine
 
 # Copy the HTML file
 COPY index.html /usr/share/nginx/html/