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>

docker/bitcoin-ui/index.html

@@ -7,7 +7,7 @@
     <meta http-equiv="Pragma" content="no-cache">
     <meta http-equiv="Expires" content="0">
     <title>Bitcoin Knots - Archipelago</title>
-    <script src="https://cdn.tailwindcss.com"></script>
+    <link rel="stylesheet" href="tailwind.css">
     <style>
         * {
             margin: 0;
@@ -35,7 +35,7 @@
         .bg-layer {
             position: absolute;
             inset: 0;
-            background-image: url('/assets/img/bg-network.jpg');
+            background-image: url('assets/img/bg-network.jpg');
             background-size: cover;
             background-position: center;
             background-repeat: no-repeat;
@@ -337,7 +337,7 @@
                 <div class="flex-shrink-0">
                     <div class="logo-gradient-border">
                         <img 
-                            src="/assets/img/app-icons/bitcoin-knots.webp"
+                            src="assets/img/app-icons/bitcoin-knots.webp"
                             alt="Bitcoin Knots" 
                             class="w-16 h-16"
                             style="object-fit: contain;"
@@ -591,7 +591,7 @@
         console.log('[Bitcoin UI] Script loaded, initializing...');
         
         // RPC Configuration - Use local Nginx proxy within container
-        const RPC_ENDPOINT = '/bitcoin-rpc/';
+        const RPC_ENDPOINT = 'bitcoin-rpc/';
         console.log('[Bitcoin UI] RPC Endpoint:', RPC_ENDPOINT);
 
         // Make RPC call to Bitcoin node via local proxy