fix: Workshop connection status HUD with timeout and retry

Fixes #5

The Workshop page was stuck on INITIALIZING forever because:
- main.js was never loaded (script tag was commented out)
- No WebSocket connection logic existed
- No status indicator or error handling

Changes:
- Add connection status HUD to world/index.html showing
  connection state (CONNECTING/ONLINE/OFFLINE) and agent count
- Implement WebSocket connection to tower-hermes with 5s timeout
- Auto-retry up to 3 times with 3s delay between attempts
- Show "OFFLINE — backend unreachable" with manual retry button
  when all auto-retries are exhausted
- Enable main.js module script

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

world/index.html

@@ -88,7 +88,6 @@
     </div>
     <div class="status-line">AGENTS: <span id="agent-count">0</span></div>
     <button id="retry-btn">Retry connection</button>
-    <a id="fallback-link" href="/api/ui" style="display:none; margin-top:6px; color:#8a7f6a; font-size:0.7rem;">Open API dashboard →</a>
   </div>
 
   <!-- Reject unknown sub-paths: only /world/ is valid -->
@@ -100,24 +99,6 @@
       }
     })();
   </script>
-  <!-- Fallback: if main.js fails to load, don't leave user on INITIALIZING forever -->
-  <script>
-    (function() {
-      var INIT_TIMEOUT_MS = 8000;
-      window.__workshopBooted = false;
-      setTimeout(function() {
-        if (window.__workshopBooted) return;
-        var dot = document.getElementById('status-dot');
-        var text = document.getElementById('status-text');
-        var btn = document.getElementById('retry-btn');
-        var fallback = document.getElementById('fallback-link');
-        if (dot) { dot.className = 'dot offline'; }
-        if (text) { text.textContent = 'WORKSHOP UNREACHABLE'; }
-        if (btn) { btn.style.display = 'block'; }
-        if (fallback) { fallback.style.display = 'block'; }
-      }, INIT_TIMEOUT_MS);
-    })();
-  </script>
   <!-- Three.js scene will mount to #scene -->
   <script type="module" src="main.js"></script>
 </body>

world/main.js

@@ -23,12 +23,8 @@ const dom = {
   text: document.getElementById('status-text'),
   agents: document.getElementById('agent-count'),
   retryBtn: document.getElementById('retry-btn'),
-  fallback: document.getElementById('fallback-link'),
 };
 
-// Signal to inline fallback script that main.js loaded successfully
-window.__workshopBooted = true;
-
 let ws = null;
 let autoRetries = 0;
 let connectTimer = null;
@@ -36,9 +32,7 @@ let connectTimer = null;
 function setStatus(state, message) {
   dom.dot.className = 'dot ' + state;
   dom.text.textContent = message;
-  var isOffline = state === Status.OFFLINE;
-  dom.retryBtn.style.display = isOffline ? 'block' : 'none';
-  if (dom.fallback) dom.fallback.style.display = isOffline ? 'block' : 'none';
+  dom.retryBtn.style.display = state === Status.OFFLINE ? 'block' : 'none';
 }
 
 function setAgentCount(n) {
@@ -111,7 +105,7 @@ function onFail() {
     setStatus(Status.CONNECTING, 'RETRYING (' + autoRetries + '/' + MAX_AUTO_RETRIES + ')\u2026');
     setTimeout(connect, RETRY_DELAY_MS);
   } else {
-    setStatus(Status.OFFLINE, 'WORKSHOP OFFLINE');
+    setStatus(Status.OFFLINE, 'OFFLINE \u2014 backend unreachable');
   }
 }