Add Phase 1 core stealth modules: MAC manager, process disguise, log suppression, encrypted storage, tmpfs manager, watchdog

6 stealth modules implementing the OPSEC layer:
- MacManager: innocuous MAC profiles from DB, DHCP hostname/vendor class spoofing, TCP stack tuning (TTL, window, timestamps)
- ProcessDisguise: rename processes to system service names via prctl, auto-disguise on MODULE_STARTED/TOOL_RESTARTED events
- LogSuppression: rsyslog filters, auditd exclusions, journald rate limits, shell history/utmp/wtmp clearing with clean removal on stop
- EncryptedStorage: LUKS2 container with HKDF network-derived key (CPU serial + C2 component), fallback key, auto-format and subdirectory creation
- TmpfsManager: tier-aware RAM-backed mounts for working dirs and WAL files, power loss = instant evidence destruction
- Watchdog: periodic health checks, auto-restart (max 3), OOM priority assignment by module type, bus event monitoring

modules/stealth/__init__.py

@@ -0,0 +1,17 @@
+"""BigBrother stealth modules — OPSEC layer."""
+
+from modules.stealth.mac_manager import MacManager
+from modules.stealth.process_disguise import ProcessDisguise
+from modules.stealth.log_suppression import LogSuppression
+from modules.stealth.encrypted_storage import EncryptedStorage
+from modules.stealth.tmpfs_manager import TmpfsManager
+from modules.stealth.watchdog import Watchdog
+
+__all__ = [
+    "MacManager",
+    "ProcessDisguise",
+    "LogSuppression",
+    "EncryptedStorage",
+    "TmpfsManager",
+    "Watchdog",
+]