Add /reset and /sessions debug commands to web client

/reset — clears all localStorage (identity, sessions, SPK)
/sessions — shows active session peers and SPK secret prefix

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

warzone/crates/warzone-server/src/routes/web.rs

@@ -571,6 +571,16 @@ async function doSend() {
   }
   if (text === '/clear') { $messages.innerHTML = ''; return; }
   if (text === '/debug') { DEBUG = !DEBUG; addSys('Debug logging: ' + (DEBUG ? 'ON (check browser console)' : 'OFF')); return; }
+  if (text === '/reset') {
+    localStorage.clear();
+    addSys('localStorage cleared. Refresh the page to start fresh.');
+    return;
+  }
+  if (text === '/sessions') {
+    addSys('Sessions: ' + Object.keys(sessions).join(', '));
+    addSys('SPK secret: ' + (mySpkSecretHex ? mySpkSecretHex.slice(0,16) + '...' : 'NONE'));
+    return;
+  }
   if (text === '/quit') { window.close(); return; }
   if (text === '/glist') { await groupList(); return; }
   if (text === '/dm') { currentGroup = null; addSys('Switched to DM mode'); $peerInput.value = localStorage.getItem('wz-peer') || ''; return; }