Add comprehensive BLE tracker detection with signature engine

Implement reliable tracker detection for AirTag, Tile, Samsung SmartTag,
and other BLE trackers based on manufacturer data patterns, service UUIDs,
and advertising payload analysis.

Key changes:
- Add TrackerSignatureEngine with signatures for major tracker brands
- Device fingerprinting to track devices across MAC randomization
- Suspicious presence heuristics (persistence, following patterns)
- New API endpoints: /api/bluetooth/trackers, /diagnostics
- UI updates with tracker badges, confidence, and evidence display
- TSCM integration updated to use v2 tracker detection data
- Unit tests and smoke test scripts for validation

Detection is heuristic-based with confidence scoring (high/medium/low)
and evidence transparency. Backwards compatible with existing APIs.

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

utils/bluetooth/models.py

@@ -20,6 +20,12 @@ from .constants import (
     PROXIMITY_UNKNOWN,
 )
 
+# Import tracker types (will be available after tracker_signatures module loads)
+# Use string type hints to avoid circular imports
+from typing import TYPE_CHECKING
+if TYPE_CHECKING:
+    from .tracker_signatures import TrackerDetectionResult, DeviceFingerprint
+
 
 @dataclass
 class BTObservation:
@@ -146,6 +152,25 @@ class BTDeviceAggregate:
     in_baseline: bool = False
     baseline_id: Optional[int] = None
 
+    # Tracker detection fields
+    is_tracker: bool = False
+    tracker_type: Optional[str] = None  # 'airtag', 'tile', 'samsung_smarttag', etc.
+    tracker_name: Optional[str] = None
+    tracker_confidence: Optional[str] = None  # 'high', 'medium', 'low', 'none'
+    tracker_confidence_score: float = 0.0  # 0.0 to 1.0
+    tracker_evidence: list[str] = field(default_factory=list)
+
+    # Suspicious presence / following heuristics
+    risk_score: float = 0.0  # 0.0 to 1.0
+    risk_factors: list[str] = field(default_factory=list)
+
+    # Payload fingerprint (survives MAC randomization)
+    payload_fingerprint_id: Optional[str] = None
+    payload_fingerprint_stability: float = 0.0
+
+    # Service data (for tracker analysis)
+    service_data: dict[str, bytes] = field(default_factory=dict)
+
     def get_rssi_history(self, max_points: int = 50) -> list[dict]:
         """Get RSSI history for sparkline visualization."""
         if not self.rssi_samples:
@@ -252,6 +277,31 @@ class BTDeviceAggregate:
             # Baseline
             'in_baseline': self.in_baseline,
             'baseline_id': self.baseline_id,
+
+            # Tracker detection
+            'tracker': {
+                'is_tracker': self.is_tracker,
+                'type': self.tracker_type,
+                'name': self.tracker_name,
+                'confidence': self.tracker_confidence,
+                'confidence_score': round(self.tracker_confidence_score, 2),
+                'evidence': self.tracker_evidence,
+            },
+
+            # Suspicious presence analysis
+            'risk_analysis': {
+                'risk_score': round(self.risk_score, 2),
+                'risk_factors': self.risk_factors,
+            },
+
+            # Fingerprint
+            'fingerprint': {
+                'id': self.payload_fingerprint_id,
+                'stability': round(self.payload_fingerprint_stability, 2),
+            },
+
+            # Raw service data for investigation
+            'service_data': {k: v.hex() for k, v in self.service_data.items()},
         }
 
     def to_summary_dict(self) -> dict:
@@ -277,6 +327,14 @@ class BTDeviceAggregate:
             'seen_count': self.seen_count,
             'heuristic_flags': self.heuristic_flags,
             'in_baseline': self.in_baseline,
+            # Tracker info for list view
+            'is_tracker': self.is_tracker,
+            'tracker_type': self.tracker_type,
+            'tracker_name': self.tracker_name,
+            'tracker_confidence': self.tracker_confidence,
+            'tracker_confidence_score': round(self.tracker_confidence_score, 2),
+            'risk_score': round(self.risk_score, 2),
+            'fingerprint_id': self.payload_fingerprint_id,
         }