refactor(01-01): convert hot-path schemas/*.py to hot_types re-export shims

- schemas/eskf.py: keep ConfidenceTier + ESKFConfig; re-export IMUSample
  and ESKFState from hot_types (define ConfidenceTier BEFORE the
  hot_types imports to avoid circular import — eskf_state.py imports
  ConfidenceTier from this module). Legacy alias IMUMeasurement = IMUSample.
- schemas/vo.py: re-export Features, Matches, RelativePose, Motion,
  VOEstimate from hot_types.vo_estimate.
- schemas/satellite.py: re-export TileCoords, TileBounds, SatelliteAnchor.
- schemas/metric.py: keep LiteSAMConfig; re-export AlignmentResult,
  ChunkAlignmentResult, Sim3Transform.
- schemas/rotation.py: keep HeadingHistory + RotationConfig; re-export
  RotationResult.

Auto-fixes (Rules 1 + 3) needed to keep the 216-test floor green:
- core/rotation.py: refactor try_rotation_steps to use
  dataclasses.replace instead of attribute assignment on RotationResult
  (Rule 1 — frozen dataclass forbids mutation; Pydantic silently allowed
  it). PATTERNS.md §6.1 already flagged Pose mutation but missed this site.
- hot_types/vo_estimate.py: add Optional `covariance: np.ndarray` field
  to RelativePose (Rule 3 — five test sites construct RelativePose with
  `covariance=np.eye(6)`; Pydantic v2 silently accepted the extra kwarg
  via default `extra="ignore"`. Declaring the field preserves the
  construction contract under the dataclass migration without editing
  tests).

Verification: pytest tests/ -q --ignore=tests/e2e → 216 passed, 8 skipped
(matches baseline). Accuracy bench (23 tests) passes.

src/gps_denied/core/rotation.py

@@ -1,5 +1,6 @@
 """Image Rotation Manager (Component F06)."""
 
+import dataclasses
 import math
 from abc import ABC, abstractmethod
 from datetime import datetime
@@ -77,8 +78,13 @@ class ImageRotationManager:
 
             if result.matched:
                 precise_angle = self.calculate_precise_angle(result.homography, float(angle))
-                result.precise_angle = precise_angle
-                result.initial_angle = float(angle)
+                # RotationResult is now a frozen dataclass (ARCH-02 / Plan 01-01);
+                # use `dataclasses.replace` instead of attribute assignment.
+                result = dataclasses.replace(
+                    result,
+                    precise_angle=precise_angle,
+                    initial_angle=float(angle),
+                )
 
                 self.update_heading(flight_id, frame_id, precise_angle, timestamp)
                 return result

src/gps_denied/hot_types/vo_estimate.py

@@ -38,7 +38,15 @@ class Matches:
 
 @dataclass(slots=True, frozen=True, eq=False)
 class RelativePose:
-    """Relative pose between two frames."""
+    """Relative pose between two frames.
+
+    Note: `covariance` is included as an optional 6×6 SE(3) uncertainty
+    matrix. The legacy Pydantic model did not declare this field but
+    silently accepted `covariance=...` kwargs (Pydantic v2 default
+    `extra="ignore"` behavior). Several stage1 tests rely on that
+    construction signature; declaring the field here preserves the
+    contract under the dataclass migration without editing tests.
+    """
 
     translation: np.ndarray    # (3,)
     rotation: np.ndarray       # (3, 3)
@@ -48,6 +56,7 @@ class RelativePose:
     tracking_good: bool
     scale_ambiguous: bool = True
     chunk_id: Optional[str] = None
+    covariance: Optional[np.ndarray] = None  # (6, 6) SE(3) covariance — optional
 
 
 @dataclass(slots=True, frozen=True, eq=False)

src/gps_denied/schemas/eskf.py

@@ -1,9 +1,16 @@
-"""Error-State Kalman Filter schemas."""
+"""Error-State Kalman Filter schemas.
+
+Phase 1 shim — hot-path types `IMUSample` (legacy: `IMUMeasurement`) and
+`ESKFState` live in `gps_denied.hot_types`. `ConfidenceTier` (enum) and
+`ESKFConfig` (Pydantic config) stay here as boundary types.
+
+`ConfidenceTier` is defined BEFORE the hot_types re-imports because
+`hot_types.eskf_state` imports `ConfidenceTier` from this module — load
+order matters to avoid a circular import.
+"""
 
 from enum import Enum
-from typing import Optional
 
-import numpy as np
 from pydantic import BaseModel
 
 
@@ -15,15 +22,6 @@ class ConfidenceTier(str, Enum):
     FAILED = "FAILED"   # 3+ consecutive total failures
 
 
-class IMUMeasurement(BaseModel):
-    """Single IMU reading from flight controller."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    accel: np.ndarray  # (3,) m/s^2 in body frame
-    gyro: np.ndarray   # (3,) rad/s in body frame
-    timestamp: float   # seconds since epoch
-
-
 class ESKFConfig(BaseModel):
     """ESKF tuning parameters."""
 
@@ -55,17 +53,22 @@ class ESKFConfig(BaseModel):
     mahalanobis_threshold: float = 16.27   # chi2(3, 0.99999) ≈ 5-sigma gate
 
 
-class ESKFState(BaseModel):
-    """Full ESKF nominal state snapshot."""
-    model_config = {"arbitrary_types_allowed": True}
+# Hot-path types — re-exported from gps_denied.hot_types (Plan 01-01).
+# Tests and existing consumers continue to import from this path; the
+# underlying type changed from a Pydantic BaseModel to a frozen dataclass.
+# These imports MUST come AFTER `ConfidenceTier` is defined above —
+# `hot_types.eskf_state` imports `ConfidenceTier` from this module.
+from gps_denied.hot_types.eskf_state import ESKFState  # noqa: E402, F401
+from gps_denied.hot_types.imu_sample import IMUSample  # noqa: E402, F401
 
-    position: np.ndarray       # (3,) ENU meters from origin (East, North, Up)
-    velocity: np.ndarray       # (3,) ENU m/s
-    quaternion: np.ndarray     # (4,) [w, x, y, z] body-to-ENU
-    accel_bias: np.ndarray     # (3,) m/s^2
-    gyro_bias: np.ndarray      # (3,) rad/s
-    covariance: np.ndarray     # (15, 15)
-    timestamp: float           # seconds since epoch
-    confidence: ConfidenceTier
-    last_satellite_time: Optional[float] = None
-    last_vo_time: Optional[float] = None
+# Legacy alias preserved until Phase 2 test taxonomy reshuffle.
+IMUMeasurement = IMUSample
+
+
+__all__ = [
+    "ConfidenceTier",
+    "ESKFConfig",
+    "ESKFState",
+    "IMUMeasurement",
+    "IMUSample",
+]

src/gps_denied/schemas/metric.py

@@ -1,46 +1,17 @@
-"""Metric Refinement schemas (Component F09)."""
+"""Metric Refinement schemas (Component F09).
 
+Phase 1 shim — hot-path types `AlignmentResult`, `ChunkAlignmentResult`,
+`Sim3Transform` live in `gps_denied.hot_types.alignment_result`.
+`LiteSAMConfig` (config) stays here as a Pydantic boundary type.
+"""
 
-import numpy as np
 from pydantic import BaseModel
 
-from gps_denied.schemas import GPSPoint
-
-
-class AlignmentResult(BaseModel):
-    """Result of aligning a UAV image to a single satellite tile."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    matched: bool
-    homography: np.ndarray  # (3, 3)
-    gps_center: GPSPoint
-    confidence: float
-    inlier_count: int
-    total_correspondences: int
-    reprojection_error: float  # Mean error in pixels
-
-
-class Sim3Transform(BaseModel):
-    """Sim(3) transformation: scale, rotation, translation."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    translation: np.ndarray  # (3,)
-    rotation: np.ndarray  # (3, 3) rotation matrix
-    scale: float
-
-
-class ChunkAlignmentResult(BaseModel):
-    """Result of aligning a chunk array of UAV images to a satellite tile."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    matched: bool
-    chunk_id: str
-    chunk_center_gps: GPSPoint
-    rotation_angle: float
-    confidence: float
-    inlier_count: int
-    transform: Sim3Transform
-    reprojection_error: float
+from gps_denied.hot_types.alignment_result import (  # noqa: F401
+    AlignmentResult,
+    ChunkAlignmentResult,
+    Sim3Transform,
+)
 
 
 class LiteSAMConfig(BaseModel):
@@ -51,3 +22,11 @@ class LiteSAMConfig(BaseModel):
     max_reprojection_error: float = 2.0  # pixels
     multi_scale_levels: int = 3
     chunk_min_inliers: int = 30
+
+
+__all__ = [
+    "AlignmentResult",
+    "ChunkAlignmentResult",
+    "LiteSAMConfig",
+    "Sim3Transform",
+]

src/gps_denied/schemas/rotation.py

@@ -1,24 +1,16 @@
-"""Rotation schemas (Component F06)."""
+"""Rotation schemas (Component F06).
+
+Phase 1 shim — hot-path `RotationResult` lives in
+`gps_denied.hot_types.rotation_result`. `HeadingHistory` (mutable
+bookkeeping) and `RotationConfig` (config) stay here as Pydantic.
+"""
 
 from datetime import datetime
 from typing import Optional
 
-import numpy as np
 from pydantic import BaseModel
 
-
-class RotationResult(BaseModel):
-    """Result of a rotation sweep alignment."""
-    matched: bool
-    initial_angle: float
-    precise_angle: float
-    confidence: float
-    # We will exclude np.ndarray from BaseModel to avoid validation issues,
-    # but store it as an attribute if needed or use arbitrary_types_allowed.
-
-    model_config = {"arbitrary_types_allowed": True}
-    homography: Optional[np.ndarray] = None
-    inlier_count: int = 0
+from gps_denied.hot_types.rotation_result import RotationResult  # noqa: F401
 
 
 class HeadingHistory(BaseModel):
@@ -36,3 +28,10 @@ class RotationConfig(BaseModel):
     sharp_turn_threshold: float = 45.0
     confidence_threshold: float = 0.7
     history_size: int = 10
+
+
+__all__ = [
+    "HeadingHistory",
+    "RotationConfig",
+    "RotationResult",
+]

src/gps_denied/schemas/satellite.py

@@ -1,22 +1,17 @@
-"""Satellite domain schemas."""
+"""Satellite domain schemas.
 
-from pydantic import BaseModel
+Phase 1 shim — `TileCoords`, `TileBounds`, and the Phase-3 placeholder
+`SatelliteAnchor` live in `gps_denied.hot_types.satellite_anchor`.
+"""
 
-from gps_denied.schemas import GPSPoint
+from gps_denied.hot_types.satellite_anchor import (  # noqa: F401
+    SatelliteAnchor,
+    TileBounds,
+    TileCoords,
+)
 
-
-class TileCoords(BaseModel):
-    """Web Mercator tile coordinates."""
-    x: int
-    y: int
-    zoom: int
-
-
-class TileBounds(BaseModel):
-    """GPS boundaries of a tile."""
-    nw: GPSPoint
-    ne: GPSPoint
-    sw: GPSPoint
-    se: GPSPoint
-    center: GPSPoint
-    gsd: float  # Ground Sampling Distance (meters/pixel)
+__all__ = [
+    "SatelliteAnchor",
+    "TileBounds",
+    "TileCoords",
+]

src/gps_denied/schemas/vo.py

@@ -1,49 +1,21 @@
-"""Sequential Visual Odometry schemas (Component F07)."""
+"""Sequential Visual Odometry schemas (Component F07).
 
-from typing import Optional
+Phase 1 shim — `Features`, `Matches`, `RelativePose`, `Motion` and the
+ARCH-02 alias `VOEstimate` live in `gps_denied.hot_types.vo_estimate`.
+"""
 
-import numpy as np
-from pydantic import BaseModel
+from gps_denied.hot_types.vo_estimate import (  # noqa: F401
+    Features,
+    Matches,
+    Motion,
+    RelativePose,
+    VOEstimate,
+)
 
-
-class Features(BaseModel):
-    """Extracted image features (e.g., from SuperPoint)."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    keypoints: np.ndarray  # (N, 2)
-    descriptors: np.ndarray  # (N, 256)
-    scores: np.ndarray  # (N,)
-
-
-class Matches(BaseModel):
-    """Matches between two sets of features (e.g., from LightGlue)."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    matches: np.ndarray  # (M, 2)
-    scores: np.ndarray  # (M,)
-    keypoints1: np.ndarray  # (M, 2)
-    keypoints2: np.ndarray  # (M, 2)
-
-
-class RelativePose(BaseModel):
-    """Relative pose between two frames."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    translation: np.ndarray  # (3,)
-    rotation: np.ndarray  # (3, 3)
-    confidence: float
-    inlier_count: int
-    total_matches: int
-    tracking_good: bool
-    scale_ambiguous: bool = True
-    chunk_id: Optional[str] = None
-
-
-class Motion(BaseModel):
-    """Motion estimate from OpenCV."""
-    model_config = {"arbitrary_types_allowed": True}
-
-    translation: np.ndarray  # (3,) unit vector
-    rotation: np.ndarray  # (3, 3) rotation matrix
-    inliers: np.ndarray  # Boolean mask of inliers
-    inlier_count: int
+__all__ = [
+    "Features",
+    "Matches",
+    "Motion",
+    "RelativePose",
+    "VOEstimate",
+]