Refactor Telegram bot and web application for improved functionality

- Disabled the default menu button in the Telegram bot, allowing users to access the app via a direct link.
- Updated the initData validation process to ensure URL-decoded values are used in the data-check string.
- Enhanced error handling in the web application to provide more informative access denial messages.
- Removed unnecessary debug information from the access denied section in the web app.
- Cleaned up the web application code by removing unused functions and improving CSS styles for hidden elements.

api/test_telegram_auth.py

@@ -3,7 +3,7 @@
 import hashlib
 import hmac
 import json
-from urllib.parse import quote
+from urllib.parse import quote, unquote
 
 
 from api.telegram_auth import validate_init_data
@@ -21,7 +21,7 @@ def _make_init_data(
     if auth_date is not None:
         params["auth_date"] = str(auth_date)
     pairs = sorted(params.items())
-    data_string = "\n".join(f"{k}={v}" for k, v in pairs)
+    data_string = "\n".join(f"{k}={unquote(v)}" for k, v in pairs)
     secret_key = hmac.new(
         b"WebAppData",
         msg=bot_token.encode(),