fix(mtproto): harden panel + deploy visibility

- Rename snapshot to snap; bust app.js cache (?v).\n- /health returns version from package.json; startup log prints v.

Co-authored-by: Cursor <cursoragent@cursor.com>

public/index.html

@@ -261,6 +261,6 @@
     </div>
   </dialog>
 
-  <script src="/app.js" type="module"></script>
+  <script src="/app.js?v=1.2.18" type="module"></script>
 </body>
 </html>