feat(01-02): add migration-target Protocols for vio/gpr/satellite_matcher/mavlink_io/coordinate_transforms (ARCH-05)

- VisualOdometry mirrors ISequentialVisualOdometry (4 methods)
- GlobalPlaceRecognition mirrors IGlobalPlaceRecognition (7 methods)
- SatelliteTileLoader mirrors SatelliteDataManager public API (11 methods)
- MetricRefiner mirrors IMetricRefinement (6 methods)
- MAVLinkBridgeProtocol mirrors MAVLinkBridge public API (8 methods)
- CoordinateTransformsProtocol mirrors CoordinateTransformer (9 methods)
- All Protocols runtime_checkable; backwards-compat I-prefixed aliases
  exposed for vio/gpr/metric (deprecated in Phase 2)
- Pure-additive: zero existing files touched
- isinstance check confirms SatelliteDataManager and CoordinateTransformer
  already satisfy the new Protocols structurally

src/gps_denied/components/mavlink_io/protocol.py

@@ -0,0 +1,39 @@
+"""Protocol surface for the MAVLink I/O component (ARCH-05).
+
+Phase 1: mirrors the concrete ``MAVLinkBridge`` public surface from
+``core/mavlink.py`` (no ABC today). Adapters move here in Plan 07
+(mavlink_io); private helpers ``_confidence_to_fix_type`` and
+``_eskf_to_gps_input`` MUST stay re-exported from the old path.
+"""
+from __future__ import annotations
+
+from typing import Callable, Optional, Protocol, runtime_checkable
+
+from gps_denied.schemas import GPSPoint
+from gps_denied.schemas.eskf import ESKFState, IMUMeasurement
+from gps_denied.schemas.mavlink import GPSInputMessage, RelocalizationRequest
+
+
+@runtime_checkable
+class MAVLinkBridgeProtocol(Protocol):
+    """Public surface of the MAVLink GPS_INPUT/IMU/telemetry bridge."""
+
+    def set_imu_callback(
+        self, cb: Callable[[IMUMeasurement], None]
+    ) -> None: ...
+
+    def set_reloc_callback(
+        self, cb: Callable[[RelocalizationRequest], None]
+    ) -> None: ...
+
+    def update_state(self, state: ESKFState, altitude_m: float = 0.0) -> None: ...
+
+    def notify_satellite_correction(self) -> None: ...
+
+    def update_drift_estimate(self, drift_m: float) -> None: ...
+
+    async def start(self, origin: GPSPoint) -> None: ...
+
+    async def stop(self) -> None: ...
+
+    def build_gps_input(self) -> Optional[GPSInputMessage]: ...