Remove deactivated Telegram provider (#2461)

Removes the TelegramProvider and TelegramBackend classes along with the
@telegram-apps/sdk dependency since the Telegram integration is no
longer supported.

## Changes
- Delete unused `TelegramProvider` and `TelegramBackend` classes
- Remove `@telegram-apps/sdk` dependency from package.json
- Update session.tsx comment to remove Telegram-specific context
- Clean up pnpm-lock.yaml

The constants and query parameter naming conventions remain unchanged as
they're used by other providers.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: kronosapiens

packages/controller/package.json

@@ -43,7 +43,6 @@
     "ethers": "^6.13.5",
     "@starknet-io/get-starknet-wallet-standard": "5.0.0-beta.0",
     "@starknet-io/types-js": "0.9.1",
-    "@telegram-apps/sdk": "^2.4.0",
     "@turnkey/sdk-browser": "^4.0.0",
     "cbor-x": "^1.5.0",
     "starknet": "^8.5.2",

packages/controller/src/telegram/backend.ts

@@ -90,8 +90,7 @@ export function Session() {
       const headers = new Headers();
       headers.append("Content-Type", "application/json");
 
-      // Remove any trailing '=' characters from the encoded response
-      // Telegram doesnt seem to be able to decode the response if there are any
+      // Remove any trailing '=' padding from the base64 encoded response
       const encodedResponse = btoa(JSON.stringify(response)).replace(/=+$/, "");
 
       if (queries.callback_uri) {