fix: BUG-33 CPU threshold, TASK-27 tab icons, TASK-36 iframe errors

- BUG-33: CPU load alert threshold increased from 2x to 4x core count
  (8→16 on 4-core machine) to reduce false alerts during container ops
- TASK-27: Launch buttons for new-tab apps now show external link icon
  (BTCPay, Grafana, PhotoPrism, Portainer, OnlyOffice, etc.)
- TASK-36: Iframe error screen now distinguishes between X-Frame-Options
  blocked vs container not reachable, with appropriate messaging

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

neode-ui/mock-backend.js

@@ -159,7 +159,8 @@ const portMappings = {
   'portainer': 9443,
   'uptime-kuma': 3001,
   'tailscale': 41641,
-  'fedimint': 8174,
+  'fedimint': 8175,
+  'thunderhub': 3010,
   'nostr-rs-relay': 7000,
   'syncthing': 8384,
   'penpot': 9001,
@@ -388,6 +389,7 @@ const marketplaceMetadata = {
   'dwn': { title: 'Decentralized Web Node', shortDesc: 'Store and sync personal data with DID-based access', icon: '/assets/img/app-icons/dwn.svg' },
   'nostr-rs-relay': { title: 'Nostr Relay', shortDesc: 'Run your own Nostr relay', icon: '/assets/img/app-icons/nostr-rs-relay.svg' },
   'syncthing': { title: 'Syncthing', shortDesc: 'Peer-to-peer file synchronization', icon: '/assets/img/app-icons/syncthing.png' },
+  'thunderhub': { title: 'ThunderHub', shortDesc: 'Lightning node management UI with channel management and payments', icon: '/assets/img/app-icons/thunderhub.svg' },
   'tor': { title: 'Tor', shortDesc: 'Anonymous communication over the Tor network', icon: '/assets/img/app-icons/tor.png' },
   'amin': { title: 'Amin', shortDesc: 'Administrative interface for Archipelago', icon: '/assets/icon/pwa-192x192-v2.png' },
 }
@@ -723,6 +725,24 @@ const staticDevApps = {
     lanPort: 8083,
     icon: '/assets/img/app-icons/file-browser.webp',
   }),
+  thunderhub: staticApp({
+    id: 'thunderhub',
+    title: 'ThunderHub',
+    version: '0.13.31',
+    shortDesc: 'Lightning node management UI',
+    longDesc: 'Full Lightning node management — channels, payments, routing fees, and node health. Connect to your LND and manage everything from one dashboard.',
+    state: 'running',
+    lanPort: 3010,
+  }),
+  fedimint: staticApp({
+    id: 'fedimint',
+    title: 'Fedimint',
+    version: '0.10.0',
+    shortDesc: 'Federated Bitcoin mint',
+    longDesc: 'Federated Chaumian e-cash mint with Guardian UI. Community custody, private payments, and Lightning gateways.',
+    state: 'running',
+    lanPort: 8175,
+  }),
 }
 
 function mergePackageData(dockerApps) {
@@ -997,12 +1017,22 @@ app.post('/rpc/v1', (req, res) => {
             id: 'fedimint',
             title: 'Fedimint',
             description: 'Federated Chaumian e-cash mint — community custody, private payments, and Lightning gateways for your tribe.',
-            version: '0.4.3',
+            version: '0.10.0',
             icon: '/assets/img/app-icons/fedimint.png',
             author: 'Fedimint',
             license: 'MIT',
             category: 'Bitcoin',
           },
+          {
+            id: 'thunderhub',
+            title: 'ThunderHub',
+            description: 'Lightning node management UI — manage channels, send and receive payments, view routing fees, and monitor your node health.',
+            version: '0.13.31',
+            icon: '/assets/img/app-icons/thunderhub.svg',
+            author: 'Anthony Potdevin',
+            license: 'MIT',
+            category: 'Bitcoin',
+          },
           {
             id: 'vaultwarden',
             title: 'Vaultwarden',
@@ -1305,7 +1335,50 @@ app.post('/rpc/v1', (req, res) => {
       }
 
       case 'node.notifications': {
-        return res.json({ result: [] })
+        return res.json({
+          result: [
+            {
+              id: 'notif-1',
+              type: 'info',
+              title: 'Bitcoin Core synced',
+              message: 'Blockchain fully synced at block 892,451. IBD complete.',
+              timestamp: new Date(Date.now() - 1800000).toISOString(),
+              read: false,
+            },
+            {
+              id: 'notif-2',
+              type: 'success',
+              title: 'LND channel opened',
+              message: 'Channel opened with ACINQ (500,000 sats capacity). 6 confirmations received.',
+              timestamp: new Date(Date.now() - 7200000).toISOString(),
+              read: false,
+            },
+            {
+              id: 'notif-3',
+              type: 'warning',
+              title: 'Disk usage above 80%',
+              message: 'Storage at 82% capacity. Consider pruning old blockchain data or expanding storage.',
+              timestamp: new Date(Date.now() - 14400000).toISOString(),
+              read: true,
+            },
+            {
+              id: 'notif-4',
+              type: 'info',
+              title: 'System update available',
+              message: 'Archipelago v0.1.1 is available. Review changelog before updating.',
+              timestamp: new Date(Date.now() - 86400000).toISOString(),
+              read: true,
+            },
+            {
+              id: 'notif-5',
+              type: 'success',
+              title: 'Fedimint guardian connected',
+              message: 'Guardian consensus achieved. Mint is operational with 3/4 guardians online.',
+              timestamp: new Date(Date.now() - 43200000).toISOString(),
+              read: false,
+            },
+          ],
+        })
       }
 
       // =====================================================================