feat(harness): init ESKF from adapter's first GT pose as synthetic GPS origin

Wires a real CoordinateTransformer into the processor and seeds the ESKF
with the dataset's first ground-truth lat/lon/alt before the frame loop.
Result on EuRoC MH_01 (100 frames):
  eskf_initialized: 0/100 → 100/100
  vo_success: 99/100 (unchanged)
  eskf_has_position: 100/100

Satellite measurements are now correctly rejected by the Mahalanobis gate
(Δ² ~10⁶) because ORB produces unit-scale translations (scale_ambiguous=True)
which drive the ESKF position to diverge rapidly. The gate is working as
intended — the remaining issue is VO metric scale, not ESKF initialisation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/gps_denied/testing/harness.py

@@ -23,6 +23,7 @@ import cv2
 import numpy as np
 
 from gps_denied.core.chunk_manager import RouteChunkManager
+from gps_denied.core.coordinates import CoordinateTransformer
 from gps_denied.core.gpr import GlobalPlaceRecognition
 from gps_denied.core.graph import FactorGraphOptimizer
 from gps_denied.core.metric import MetricRefinement
@@ -30,6 +31,7 @@ from gps_denied.core.models import ModelManager
 from gps_denied.core.processor import FlightProcessor
 from gps_denied.core.recovery import FailureRecoveryCoordinator
 from gps_denied.core.vo import ORBVisualOdometry
+from gps_denied.schemas import GPSPoint
 from gps_denied.schemas.graph import FactorGraphConfig
 from gps_denied.testing.datasets.base import (
     DatasetAdapter,
@@ -88,6 +90,16 @@ class E2EHarness:
         for i, pose in enumerate(gt_poses):
             gt_by_idx[i] = pose
 
+        # Seed ESKF with first GT pose as synthetic GPS origin so the processor
+        # can propagate VO translations into a consistent ENU frame.
+        if gt_poses:
+            origin = gt_poses[0]
+            start_gps = GPSPoint(lat=origin.lat, lon=origin.lon)
+            processor._coord.set_enu_origin(self._flight_id, start_gps)  # noqa: SLF001
+            processor._init_eskf_for_flight(  # noqa: SLF001
+                self._flight_id, start_gps, altitude=origin.alt
+            )
+
         trace_fh = None
         if self._trace_path is not None:
             self._trace_path.parent.mkdir(parents=True, exist_ok=True)
@@ -182,9 +194,11 @@ class E2EHarness:
         graph = FactorGraphOptimizer(FactorGraphConfig())
         chunk_mgr = RouteChunkManager(graph)
         recovery = FailureRecoveryCoordinator(chunk_mgr, gpr, metric)
+        coord = CoordinateTransformer()
         proc.attach_components(
             vo=vo, gpr=gpr, metric=metric,
             graph=graph, recovery=recovery, chunk_mgr=chunk_mgr,
+            coord=coord,
         )
         return proc