[Testing] Test coverage >80% with pytest

[OneByJorah]

Test Coverage Checklist

• Add pytest configuration (pytest.ini or pyproject.toml)
• Add test dependencies (pytest, pytest-asyncio, pytest-cov, pytest-mock, httpx)
• Write unit tests for all modules (bot, discovery, agents, dashboard, scheduler)
• Write integration tests for agent communication
• Write tests for SNMP scanning
• Write tests for Telegram bot handlers
• Achieve >80% code coverage
• Add coverage reporting to CI
• Add mutation testing (mutmut)