Fix #206: Resolve auto interface to actual interface name

- Engine.__init__ now detects actual interface when config has 'auto'
- Uses get_primary_interface() to find default route interface
- PacketCapture module updated to use detected interface with fallback
- Handles Pi Zero 2W (wlan0) and other non-eth0 systems

core/engine.py

@@ -24,6 +24,7 @@ from typing import Optional, Type
 from core.bus import EventBus, Event
 from core.state import StateManager
 from modules.base import BaseModule
+from utils.networking import get_primary_interface
 
 logger = logging.getLogger("bb.engine")
 
@@ -217,6 +218,13 @@ class Engine:
         self._tier_limits = HARDWARE_TIERS.get(self._tier, HARDWARE_TIERS["generic"])
         self._scope = config.get("scope", {})
         self._phase = config.get("engagement_phase", {}).get("mode", "passive_only")
+
+        # Resolve "auto" interface to actual interface name
+        if self.config.get("network", {}).get("primary_interface") == "auto":
+            actual_iface = get_primary_interface()
+            if actual_iface:
+                self.config.setdefault("network", {})["primary_interface"] = actual_iface
+                logger.debug("Resolved auto interface to: %s", actual_iface)
         self._lock = multiprocessing.Lock()
         logger.info("Engine initialized (tier=%s, phase=%s)", self._tier, self._phase)