Add Telegram cancellation import functionality with tests and documentation

- Implemented Telegram cancellation parsing logic in `telegramCancellationParser.js`.
- Created unit tests for cancellation parsing in `telegramCancellationParser.test.js`.
- Developed integration tests for Telegram import service in `telegramImport.integration.test.js`.
- Added API tests for Telegram import endpoints in `telegramImportApi.test.js`.
- Introduced service tests for Telegram import logic in `telegramImportService.test.js`.
- Documented the Telegram cancellation import process in `telegram-cancellation-import.md`.
- Built a React component for managing Telegram imports in `TelegramImportPanel.jsx`.

.gitignore

@@ -39,6 +39,9 @@ nginx/ssl/
 
 # Runtime secrets
 secrets/
+*.session
+*.session-journal
+telegram-session*
 
 # Temp files
 *.tmp