fix: bridge pairing + auto-reconnect + test stability

Bridge mode rewrite:
- First client echoes while waiting, checks every 100ms if paired
- Second client triggers bridge immediately, first exits echo loop
- After bridge ends, slot is cleared for the next pair
- No more two tasks competing for the same transport recv

Web client auto-reconnect:
- On WebSocket close/error, automatically reconnects after 1s
- Keeps retrying as long as the user hasn't clicked Disconnect

Test fix:
- Install rustls crypto provider in transport config tests
  (fixes race condition when running full workspace tests)

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

crates/wzp-web/static/index.html

@@ -99,13 +99,22 @@ async function startCall() {
   };
 
   ws.onclose = () => {
-    setStatus('Disconnected');
-    stopCall();
+    if (active) {
+      setStatus('Disconnected — reconnecting...');
+      setTimeout(() => { if (active) { stopCall(); startCall(); } }, 1000);
+    } else {
+      setStatus('Disconnected');
+    }
   };
 
   ws.onerror = (e) => {
-    setStatus('Connection error');
-    stopCall();
+    if (active) {
+      setStatus('Connection error — reconnecting...');
+      setTimeout(() => { if (active) { stopCall(); startCall(); } }, 1000);
+    } else {
+      setStatus('Connection error');
+      stopCall();
+    }
   };
 }