fix: terminal WebSocket connection timing + better mock fallback

- Fix xterm.js container not found: use requestAnimationFrame retry loop
  instead of single $nextTick (Alpine x-for renders asynchronously)
- Better mock fallback: use host name+IP instead of raw UUID
- Add logging for WebSocket connection path (found/not-found/hostname)

app/backend/static/js/terminal.js

@@ -108,13 +108,16 @@ document.addEventListener('alpine:init', () => {
 
       this._createTerminal(id, host.name);
 
-      this.$nextTick(() => {
+      const tryOpen = (retries) => {
         const container = document.getElementById('xterm-' + id);
         if (container) {
           this.terminals[id].open(container);
           this._connectWebSocket(id, host.id, host.name);
+        } else if (retries > 0) {
+          requestAnimationFrame(() => tryOpen(retries - 1));
         }
-      });
+      };
+      this.$nextTick(() => tryOpen(10));
     },
 
     switchTab(i) {