feat: bitcoin-ui CSS fix, HTTPS proxy support, deploy script improvements

Bitcoin UI:
- Replace cdn.tailwindcss.com with locally bundled tailwind.css (CSP blocks external scripts)
- Make all asset paths relative for nginx proxy compatibility
- Add bitcoin-ui build/deploy to deploy-to-target.sh (was missing entirely)
- Use --network host (bitcoin-ui proxies Bitcoin RPC at 127.0.0.1:8332)

HTTPS mixed content fix:
- Add HTTPS_PROXY_PATHS in AppSession.vue — when parent page is HTTPS,
  iframe loads through nginx proxy instead of direct HTTP port
- Prevents browser blocking HTTP iframes inside HTTPS pages
- All Tailscale servers use HTTPS, this was breaking all app iframes

Deploy & first-boot improvements:
- first-boot-containers.sh auto-detects disk size for pruning vs txindex
- first-boot-containers.sh checks fallback source path for UI containers
- Added mempool-electrs to APP_PORTS mapping
- ElectrumX container creation in first-boot
- Podman doctor/fix/uptime skills added

Also includes: session persistence, identity management, LND transactions,
ElectrumX status UI, nostr-provider improvements, Web5 enhancements

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

image-recipe/configs/snippets/archipelago-https-app-proxies.conf

@@ -218,7 +218,7 @@ location /app/bitcoin-ui/ {
     sub_filter_once on;
     sub_filter '</head>' '<script src="/nostr-provider.js"></script></head>';
 }
-location /app/electrs/ {
+location /app/electrumx/ {
     proxy_pass http://127.0.0.1:50002/;
     proxy_http_version 1.1;
     proxy_set_header Host $host;