Fix #211: Remove tool identity strings from deployed artifacts

- Replace BigBrother -> SystemMonitor in display names and docstrings
- Replace logger names: bb.* -> sensor.*
- Replace process names: bb-* -> sensor-*
- Replace home directory: ~/.bigbrother -> ~/.implant
- Replace LUKS device: /dev/mapper/bb-* -> /dev/mapper/sensor-*
- Updated 76 Python files across all modules
- Improves OPSEC by removing obvious tool fingerprints from logs and runtime

tests/conftest.py

@@ -1,4 +1,4 @@
-"""Shared pytest fixtures for BigBrother tests."""
+"""Shared pytest fixtures for SystemMonitor tests."""
 
 import os
 import sys
@@ -31,7 +31,7 @@ def tmp_dir(tmp_path):
 
 @pytest.fixture
 def mock_config():
-    """Return a valid BigBrother config dict (no YAML file needed)."""
+    """Return a valid SystemMonitor config dict (no YAML file needed)."""
     return {
         "device": {
             "platform": "generic",