feat(perception): add dual evidence replay threat

src/k1link/perception/geometry.py

@@ -245,6 +245,48 @@ class RecordedGeometryStore:
         points.setflags(write=False)
         return points
 
+    def pose_values_for_frame(
+        self,
+        frame_id: str,
+    ) -> tuple[tuple[float, float, float], tuple[float, float, float, float]] | None:
+        """Return one verified replay pose without exposing the source archive."""
+
+        prefix = "frame-"
+        if not frame_id.startswith(prefix) or not frame_id[len(prefix) :].isdigit():
+            raise GeometryProviderError("replay pose frame identity is invalid")
+        frame_index = int(frame_id[len(prefix) :])
+        if not 0 <= frame_index < self.profile.frame_count:
+            raise GeometryProviderError("replay pose frame is outside the source profile")
+        if not bool(self._source["sample_available"][frame_index]):
+            return None
+        position = np.asarray(
+            self._source["pose_positions_map"][frame_index],
+            dtype=np.float64,
+        )
+        orientation = np.asarray(
+            self._source["pose_quaternions_map_from_lidar"][frame_index],
+            dtype=np.float64,
+        )
+        if not np.isfinite(position).all() or not np.isfinite(orientation).all():
+            raise GeometryProviderError("available replay pose is not finite")
+        return (
+            (float(position[0]), float(position[1]), float(position[2])),
+            (
+                float(orientation[0]),
+                float(orientation[1]),
+                float(orientation[2]),
+                float(orientation[3]),
+            ),
+        )
+
+    def available_frame_indices(self) -> tuple[int, ...]:
+        """Expose the immutable availability partition for deterministic sampling."""
+
+        return tuple(
+            int(index)
+            for index in np.flatnonzero(self._source["sample_available"])
+        )
+
     def _validate(self) -> None:
         source_required = {
             "frame_indices",