diff --git a/ui/src/lib/app.svelte.ts b/ui/src/lib/app.svelte.ts
index fd76fae..58822d8 100644
--- a/ui/src/lib/app.svelte.ts
+++ b/ui/src/lib/app.svelte.ts
@@ -751,8 +751,19 @@ async function bootVK(): Promise<void> {
   for (let attempt = 0; ; attempt++) {
     try {
       await adoptSession(await gateway.authVK(params, displayName));
-      // A VK direct-link deep link (vk.com/app<id>#<param>) rides in as the `hash` launch param.
-      if (!app.blocked) await routeStartParam(vkStartParam());
+      // A VK direct-link deep link (vk.com/app<id>?hash=<param>) rides in as the `hash` launch param.
+      const sp = vkStartParam();
+      const diag = app.blocked ? 'blocked' : await routeStartParam(sp);
+      // TEMP VK deep-link diagnostic (remove after the contour catch): VK launches are not
+      // reproducible locally and the cold-boot path lands unexpectedly on the lobby, so surface
+      // the raw query, the parsed payload, the redeem outcome and the final route.
+      console.log('[VK deeplink]', {
+        rawSearch: typeof location !== 'undefined' ? location.search : '',
+        hash: sp,
+        outcome: diag,
+        route: router.route.name,
+      });
+      showToast(`VK dl: "${sp || '∅'}" -> ${diag}`);
       app.bootError = false;
       return;
     } catch (err) {
@@ -814,12 +825,12 @@ export async function retryTelegramLaunch(): Promise<void> {
  * specific game, the friends screen with a friend-code redemption, or the lobby
  * (where invitations surface as a badge).
  */
-async function routeStartParam(param: string): Promise<void> {
+async function routeStartParam(param: string): Promise<string> {
   const link = parseStartParam(param);
   switch (link.kind) {
     case 'game':
       navigate(`/game/${link.id}`);
-      return;
+      return 'game:' + link.id;
     case 'friendCode':
       try {
         const friend = await gateway.friendCodeRedeem(link.code);
@@ -832,6 +843,7 @@ async function routeStartParam(param: string): Promise<void> {
           showToast(t('friends.added', { name: friend.displayName }));
         }
         void refreshNotifications();
+        return 'friendCode ok: ' + friend.displayName;
       } catch (err) {
         const code = err instanceof GatewayError ? err.code : '';
         if (code === 'self_relation') {
@@ -839,19 +851,22 @@ async function routeStartParam(param: string): Promise<void> {
           // scary "can't do that to yourself" error.
           navigate('/friends');
           showToast(t('friends.selfInvite'));
+          return 'friendCode self_relation';
         } else if (code === 'friend_code_invalid') {
           // A previously shared link whose single-use, 12h code is already spent or expired:
           // land in the lobby and gently point at the bot, rather than a red error on Friends.
           navigate('/');
           app.staleInvite = true;
+          return 'friendCode invalid/stale -> lobby';
         } else {
           navigate('/friends');
           handleError(err);
+          return 'friendCode err: ' + (code || 'unknown');
         }
       }
-      return;
     default:
       navigate('/');
+      return 'lobby (empty/unknown param)';
   }
 }