Refactor logging, clean dead code, fix temp files and async tasks

- Replace f-string logging with % formatting throughout
- Fix create_temp_file: use mkstemp() instead of mkdtemp() (no leaked dirs)
- Add cleanup background thread and copy.deepcopy to AsyncTaskManager
- Fix transcribe_audio_async signature to accept transcription_service + params
- Use resample_poly instead of scipy_resample for better audio quality
- Remove unused validate_file/BinaryIO methods from FileValidator
- Add requests to requirements.txt
- Add error handling for pip install in server.sh
- Add __all__ and module docstrings to __init__.py files

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/__init__.py

@@ -3,6 +3,8 @@
 и запуска сервиса распознавания речи.
 """
 
+__all__ = ['WhisperServiceAPI']
+
 import os
 import logging
 from flask import Flask
@@ -68,7 +70,7 @@ class WhisperServiceAPI:
 
     def run(self) -> None:
         """Запуск сервиса через Waitress."""
-        self.logger.info(f"Запуск сервиса на 0.0.0.0:{self.port}")
+        self.logger.info("Запуск сервиса на 0.0.0.0:%s", self.port)
         waitress.serve(self.app, host='0.0.0.0', port=self.port)
 
     def create_app(self) -> Flask: