refactor: unify logging to standard logging.getLogger(__name__) pattern

Replace custom get_logger() wrapper with standard Python logging pattern
across executor.py and quarantine.py. Remove dead logger imports from
reports.py. Remove get_logger() function from logging_config.py and its
tests. Reduces logging patterns from 2 to 1.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tests/test_logging.py

@@ -8,7 +8,6 @@ import pytest
 from vlm.logging_config import (
     MAX_LOG_SIZE,
     default_log_dir,
-    get_logger,
     log_operation,
     setup_logging,
 )
@@ -239,28 +238,6 @@ class TestLogRotation:
         assert log_file.stat().st_size < MAX_LOG_SIZE
 
 
-class TestGetLogger:
-    """Test get_logger function."""
-    
-    def test_get_logger_returns_logger(self):
-        """Test that get_logger returns a logger instance."""
-        logger = get_logger()
-        
-        assert logger is not None
-        assert logger.name == "vlm"
-    
-    def test_get_logger_creates_default_config(self):
-        """Test that get_logger creates default configuration if needed."""
-        # Clear any existing handlers
-        logger = logging.getLogger("vlm")
-        logger.handlers.clear()
-        
-        # Get logger should set up default configuration
-        logger = get_logger()
-        
-        assert len(logger.handlers) > 0
-
-
 class TestLogOperation:
     """Test log_operation helper function."""