[AZ-599] Batch 79: FT-P-02 Derkachi builder + _common.py extraction

- Add build_p02_fixtures.py: IMU CSV → tlog conversion (RAW_IMU +
  ATTITUDE pairs, centidegrees→radians yaw) and orchestrator that
  runs gps-denied replay against Derkachi MP4 + generated tlog,
  verifying ≥1 record_type="estimate" in the FDR archive.
- Extract run_gps_denied_replay + FDR-parent-dir helpers into
  sitl_replay_builder/_common.py; refactor build_p01_fixtures.py
  to import from _common (b78 tests preserved).
- Add 20 unit tests under e2e/_unit_tests/fixtures/test_sitl_
  replay_builder_p02.py covering AC-1..AC-5; total unit suite
  686/686 passing (regression gate AC-6).
- README updated to document FT-P-01 + FT-P-02 builders.
- Advance autodev state: last_completed_batch=79, current_batch=80;
  prune verbose detail blob.

Co-authored-by: Cursor <cursoragent@cursor.com>

e2e/_unit_tests/fixtures/test_sitl_replay_builder_p02.py

@@ -0,0 +1,324 @@
+"""Unit tests for `e2e/fixtures/sitl_replay_builder/build_p02_fixtures.py` (AZ-599).
+
+All external dependencies (pymavlink, subprocess) are injected via the
+underscore-prefixed parameters. The IMU CSV is small enough that we
+hand-author it inline for each test rather than depending on the real
+Derkachi data file.
+"""
+
+from __future__ import annotations
+
+import csv
+import json
+import math
+import subprocess
+from pathlib import Path
+from typing import Sequence
+from unittest.mock import MagicMock
+
+import pytest
+
+import e2e.fixtures.sitl_replay_builder.build_p02_fixtures as bp02
+
+
+_HEADER_ROW = (
+    "timestamp(ms),Time,SCALED_IMU2.xacc,SCALED_IMU2.yacc,SCALED_IMU2.zacc,"
+    "SCALED_IMU2.xgyro,SCALED_IMU2.ygyro,SCALED_IMU2.zgyro,"
+    "SCALED_IMU2.xmag,SCALED_IMU2.ymag,SCALED_IMU2.zmag,"
+    "GLOBAL_POSITION_INT.lat,GLOBAL_POSITION_INT.lon,GLOBAL_POSITION_INT.alt,"
+    "GLOBAL_POSITION_INT.relative_alt,GLOBAL_POSITION_INT.vx,GLOBAL_POSITION_INT.vy,"
+    "GLOBAL_POSITION_INT.vz,GLOBAL_POSITION_INT.hdg"
+)
+
+
+def _write_imu_csv(path: Path, rows: list[list]) -> None:
+    """Write a CSV with the full Derkachi header + the supplied data rows."""
+    path.parent.mkdir(parents=True, exist_ok=True)
+    with path.open("w", newline="", encoding="utf-8") as fp:
+        fp.write(_HEADER_ROW + "\n")
+        writer = csv.writer(fp)
+        for row in rows:
+            writer.writerow(row)
+
+
+def _good_row(ts_ms: float, hdg: int = 35041) -> list:
+    """One well-formed Derkachi row at `ts_ms` and heading `hdg` cdeg."""
+    return [
+        ts_ms, 0.0,
+        21, -3, -984,
+        52, 32, -5,
+        312, -1048, 442,
+        50_080_963_4, 36_111_544_2, 141_290, 23_182,
+        -4, -6, -88,
+        hdg,
+    ]
+
+
+# convert_imu_csv_to_tlog
+
+
+def test_convert_imu_csv_missing_file_raises(tmp_path: Path):
+    # Assert
+    with pytest.raises(FileNotFoundError, match="IMU CSV not found"):
+        bp02.convert_imu_csv_to_tlog(
+            tmp_path / "missing.csv", tmp_path / "out.tlog",
+            _mavlink_writer_factory=lambda out: MagicMock(),
+        )
+
+
+def test_convert_imu_csv_empty_raises(tmp_path: Path):
+    # Arrange — header only, no data rows
+    csv_path = tmp_path / "imu.csv"
+    _write_imu_csv(csv_path, [])
+
+    # Assert
+    with pytest.raises(ValueError, match="IMU CSV is empty"):
+        bp02.convert_imu_csv_to_tlog(
+            csv_path, tmp_path / "out.tlog",
+            _mavlink_writer_factory=lambda out: MagicMock(),
+        )
+
+
+def test_convert_imu_csv_missing_required_column_raises(tmp_path: Path):
+    # Arrange — header missing `GLOBAL_POSITION_INT.hdg`
+    csv_path = tmp_path / "imu.csv"
+    csv_path.write_text("timestamp(ms),Time\n0,0\n")
+
+    # Assert
+    with pytest.raises(ValueError, match="missing required columns"):
+        bp02.convert_imu_csv_to_tlog(
+            csv_path, tmp_path / "out.tlog",
+            _mavlink_writer_factory=lambda out: MagicMock(),
+        )
+
+
+def test_convert_imu_csv_malformed_numeric_raises(tmp_path: Path):
+    # Arrange — second-to-last value (xacc) is non-numeric
+    csv_path = tmp_path / "imu.csv"
+    row = _good_row(0.0)
+    row[2] = "not-a-number"
+    _write_imu_csv(csv_path, [row])
+
+    # Assert
+    with pytest.raises(ValueError, match="malformed IMU CSV row"):
+        bp02.convert_imu_csv_to_tlog(
+            csv_path, tmp_path / "out.tlog",
+            _mavlink_writer_factory=lambda out: MagicMock(),
+        )
+
+
+def test_convert_imu_csv_writes_pair_per_row(tmp_path: Path):
+    # Arrange
+    csv_path = tmp_path / "imu.csv"
+    _write_imu_csv(csv_path, [_good_row(0.0), _good_row(100.0), _good_row(200.0)])
+    writer = MagicMock(write=MagicMock(), close=MagicMock())
+
+    # Act
+    pairs = bp02.convert_imu_csv_to_tlog(
+        csv_path, tmp_path / "out.tlog",
+        _mavlink_writer_factory=lambda out: writer,
+    )
+
+    # Assert — 3 rows → 3 pairs → 6 message writes
+    assert pairs == 3
+    assert writer.write.call_count == 6
+    assert writer.close.call_count == 1
+
+
+def test_convert_imu_csv_real_pymavlink_round_trip(tmp_path: Path):
+    """Sanity-check the real packers; tlog file is well-formed."""
+    # Arrange
+    csv_path = tmp_path / "imu.csv"
+    _write_imu_csv(csv_path, [_good_row(0.0), _good_row(100.0)])
+
+    # Act — use real pymavlink (it's in pyproject.toml deps)
+    pairs = bp02.convert_imu_csv_to_tlog(csv_path, tmp_path / "out.tlog")
+
+    # Assert
+    assert pairs == 2
+    assert (tmp_path / "out.tlog").stat().st_size > 0
+
+
+# _hdg_centideg_to_rad
+
+
+@pytest.mark.parametrize(
+    "centideg,expected_rad",
+    [
+        (0, 0.0),
+        (9000, math.pi / 2),
+        (18000, math.pi),
+        (27000, 3 * math.pi / 2),
+        (35990, 35990 * math.pi / 18000),
+    ],
+)
+def test_hdg_centideg_to_rad(centideg: int, expected_rad: float):
+    # Assert
+    assert bp02._hdg_centideg_to_rad(centideg) == pytest.approx(expected_rad)
+
+
+# verify_fdr_has_estimates
+
+
+def _write_jsonl(path: Path, records: list[dict]) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text("\n".join(json.dumps(r) for r in records))
+
+
+def test_verify_fdr_missing_file_raises(tmp_path: Path):
+    # Assert
+    with pytest.raises(FileNotFoundError, match="FDR JSONL not found"):
+        bp02.verify_fdr_has_estimates(tmp_path / "missing.jsonl")
+
+
+def test_verify_fdr_no_estimates_raises(tmp_path: Path):
+    # Arrange
+    fdr = tmp_path / "fdr.jsonl"
+    _write_jsonl(fdr, [
+        {"record_type": "other", "payload": {}},
+        {"record_type": "imu_tick", "payload": {}},
+    ])
+
+    # Assert
+    with pytest.raises(ValueError, match="zero estimate records"):
+        bp02.verify_fdr_has_estimates(fdr)
+
+
+def test_verify_fdr_counts_estimates(tmp_path: Path):
+    # Arrange
+    fdr = tmp_path / "fdr.jsonl"
+    _write_jsonl(fdr, [
+        {"record_type": "estimate", "payload": {}},
+        {"record_type": "other", "payload": {}},
+        {"record_type": "estimate", "payload": {}},
+        {"record_type": "estimate", "payload": {}},
+    ])
+
+    # Act
+    count = bp02.verify_fdr_has_estimates(fdr)
+
+    # Assert
+    assert count == 3
+
+
+def test_verify_fdr_tolerates_malformed_lines(tmp_path: Path):
+    # Arrange — one bad JSON line interleaved with good estimate records
+    fdr = tmp_path / "fdr.jsonl"
+    fdr.write_text(
+        json.dumps({"record_type": "estimate"}) + "\n"
+        + "{not valid json\n"
+        + json.dumps({"record_type": "estimate"}) + "\n"
+    )
+
+    # Act
+    count = bp02.verify_fdr_has_estimates(fdr)
+
+    # Assert
+    assert count == 2
+
+
+# build_p02_fixtures end-to-end (mocked)
+
+
+def test_build_p02_missing_video_raises(tmp_path: Path):
+    # Arrange
+    derkachi_dir = tmp_path / "derkachi"
+    derkachi_dir.mkdir()
+    (derkachi_dir / "data_imu.csv").write_text(_HEADER_ROW + "\n")
+
+    cfg = bp02.P02BuilderConfig(
+        derkachi_dir=derkachi_dir, output_dir=tmp_path / "out",
+    )
+
+    # Assert
+    with pytest.raises(FileNotFoundError, match="Derkachi MP4 not found"):
+        bp02.build_p02_fixtures(cfg)
+
+
+def test_build_p02_missing_csv_raises(tmp_path: Path):
+    # Arrange
+    derkachi_dir = tmp_path / "derkachi"
+    derkachi_dir.mkdir()
+    (derkachi_dir / "flight_derkachi.mp4").touch()
+
+    cfg = bp02.P02BuilderConfig(
+        derkachi_dir=derkachi_dir, output_dir=tmp_path / "out",
+    )
+
+    # Assert
+    with pytest.raises(FileNotFoundError, match="Derkachi IMU CSV not found"):
+        bp02.build_p02_fixtures(cfg)
+
+
+def test_build_p02_end_to_end_with_mocks(tmp_path: Path):
+    # Arrange
+    derkachi_dir = tmp_path / "derkachi"
+    output_dir = tmp_path / "out"
+    derkachi_dir.mkdir()
+    (derkachi_dir / "flight_derkachi.mp4").touch()
+    _write_imu_csv(derkachi_dir / "data_imu.csv", [_good_row(0.0), _good_row(100.0)])
+
+    def fake_runner(cmd):
+        fdr_path = Path(cmd[cmd.index("--fdr-out") + 1])
+        _write_jsonl(fdr_path, [
+            {"record_type": "estimate", "payload": {"lat_deg": 50.0, "lon_deg": 36.0}},
+            {"record_type": "estimate", "payload": {"lat_deg": 50.1, "lon_deg": 36.1}},
+        ])
+        return subprocess.CompletedProcess(cmd, 0)
+
+    cfg = bp02.P02BuilderConfig(
+        derkachi_dir=derkachi_dir, output_dir=output_dir,
+        fc_kind="ardupilot", host="sitl-host",
+    )
+
+    # Act
+    result = bp02.build_p02_fixtures(
+        cfg,
+        _runner=fake_runner,
+        _mavlink_writer_factory=lambda out: MagicMock(write=MagicMock(), close=MagicMock()),
+    )
+
+    # Assert
+    assert result == output_dir
+    assert (output_dir / "fdr" / "fdr.jsonl").is_file()
+    observer = json.loads((output_dir / "observer_ardupilot_sitl-host.json").read_text())
+    assert observer["gps_state"]["primary_source"] == "MAV"
+
+
+def test_build_p02_propagates_verify_failure(tmp_path: Path):
+    # Arrange — fake runner writes an FDR with no estimates; default verifier raises.
+    derkachi_dir = tmp_path / "derkachi"
+    derkachi_dir.mkdir()
+    (derkachi_dir / "flight_derkachi.mp4").touch()
+    _write_imu_csv(derkachi_dir / "data_imu.csv", [_good_row(0.0)])
+
+    def fake_runner(cmd):
+        fdr_path = Path(cmd[cmd.index("--fdr-out") + 1])
+        _write_jsonl(fdr_path, [{"record_type": "imu_tick"}])
+        return subprocess.CompletedProcess(cmd, 0)
+
+    cfg = bp02.P02BuilderConfig(
+        derkachi_dir=derkachi_dir, output_dir=tmp_path / "out",
+    )
+
+    # Assert
+    with pytest.raises(ValueError, match="zero estimate records"):
+        bp02.build_p02_fixtures(
+            cfg,
+            _runner=fake_runner,
+            _mavlink_writer_factory=lambda out: MagicMock(write=MagicMock(), close=MagicMock()),
+        )
+
+
+# `_common.py` is shared with b78
+
+
+def test_common_module_exports_used_by_b01():
+    """AC-5: b78 builder still imports from _common.py after refactor."""
+    # Arrange
+    import e2e.fixtures.sitl_replay_builder.build_p01_fixtures as bp01
+    import e2e.fixtures.sitl_replay_builder._common as common
+
+    # Assert
+    assert bp01.run_gps_denied_replay is common.run_gps_denied_replay
+    assert bp01.write_observer_fixture is common.write_observer_fixture

e2e/_unit_tests/test_directory_layout.py

@@ -58,7 +58,9 @@ E2E_ROOT = Path(__file__).resolve().parents[1]
         "runner/helpers/fc_proxy_runtime.py",
         "runner/helpers/replay_mode.py",
         "fixtures/sitl_replay_builder/__init__.py",
+        "fixtures/sitl_replay_builder/_common.py",
         "fixtures/sitl_replay_builder/build_p01_fixtures.py",
+        "fixtures/sitl_replay_builder/build_p02_fixtures.py",
         "fixtures/sitl_replay_builder/README.md",
         "fixtures/mock-suite-sat/Dockerfile",
         "fixtures/mock-suite-sat/app.py",