chore(release): archive ISO build recipes, tarball-only releases

Releases no longer ship as bootable ISOs. Archipelago updates are
distributed as the backend binary plus a frontend tarball referenced by
releases/manifest.json. Nodes OTA-update via scripts/self-update.sh.

Filebrowser and AIUI remain bundled inside the frontend tarball and
deployed atomically, verified present in v1.7.43-alpha release artifact
(189 AIUI files, filebrowser-client bundle).

Archived under image-recipe/_archived/ (resurrectable if ISO distribution
is reintroduced):
  - build-auto-installer-iso.sh
  - build-unbundled-iso.sh
  - test-iso-qemu.sh
  - scripts/convert-iso-to-disk.sh
  - BUILD-ISO-STATUS.md, ISO-BUILD-CHECKLIST.md
  - branding/isohdpfx.bin
  - .gitea/workflows/build-iso-dev.yml

Updated release process docs to drop ISO references:
  - scripts/create-release.sh (next-steps text)
  - docs/BETA-RELEASE-CHECKLIST.md
  - docs/hotfix-process.md
  - README.md

image-recipe/_archived/BUILD-ISO-STATUS.md

@@ -0,0 +1,86 @@
+# Archipelago ISO Build - Quick Guide
+
+## TL;DR - Build ISO with Live Server State
+
+```bash
+cd ~/archy/image-recipe
+sudo bash build-auto-installer-iso.sh
+```
+
+The script will automatically:
+1. Try to capture backend from `/usr/local/bin/archipelago`
+2. Try to capture frontend from `/opt/archipelago/web-ui`
+3. Fall back to building from source if capture fails
+
+## Build Modes
+
+### Default: Capture from Dev Server (RECOMMENDED)
+```bash
+# From your Mac (captures from remote dev server):
+cd image-recipe
+DEV_SERVER=archipelago@192.168.1.228 sudo bash build-auto-installer-iso.sh
+
+# From the dev server itself:
+cd ~/archy/image-recipe
+sudo bash build-auto-installer-iso.sh
+```
+
+### Alternative: Build from Source
+```bash
+BUILD_FROM_SOURCE=1 sudo bash build-auto-installer-iso.sh
+```
+
+## Known Issues & Workarounds
+
+### Issue: Can't capture from localhost via SCP
+
+**Problem**: When running on the server itself, `scp localhost:/path` doesn't work.
+
+**Workaround**: Use direct file copy instead:
+```bash
+# Instead of building on the server, build from your Mac:
+cd ~/Projects/archy/image-recipe
+DEV_SERVER=archipelago@192.168.1.228 sudo bash build-auto-installer-iso.sh
+```
+
+### Issue: Podman registry not configured
+
+**Problem**: Podman can't pull images because `/etc/containers/registries.conf` has no unqualified-search registries.
+
+**Fix**:
+```bash
+ssh archipelago@192.168.1.228
+sudo tee -a /etc/containers/registries.conf <<EOF
+[registries.search]
+registries = ['docker.io']
+EOF
+```
+
+## Flash ISO to USB
+
+```bash
+cd ~/Projects/archy/image-recipe
+./write-usb-dd.sh /dev/diskX
+```
+
+## What Gets Captured
+
+From your dev server (192.168.1.228):
+- ✅ Backend binary: `/usr/local/bin/archipelago` (6.2M)
+- ✅ Frontend: `/opt/archipelago/web-ui` (~64M)
+- ✅ Nginx config: `/etc/nginx/sites-available/default`
+- ✅ Systemd service: `/etc/systemd/system/archipelago.service`
+- ✅ App manifests: `~/archy/apps/`
+
+## Current Status
+
+**Latest Working ISO**: `archipelago-debian-13-x86_64.iso` (469M, built 18:28)
+- This ISO was built earlier today
+- Contains the auto-installer
+- **Should be tested** - might already have your live server state
+
+## Next Steps
+
+1. **Flash the existing ISO** and test it on the Dell OptiPlex
+2. **Fix the build script** to properly capture from localhost (use `cp` instead of `scp`)
+3. **Configure Podman registries** on dev server for fallback source builds