feat(gp2rs): emit lyrics + vocal_pitch sidecars from GP vocal tracks

GP files with a vocal track previously produced only the legacy vocals
arrangement XML; the melody sidecar converter existed but was never
wired, so imported paks had no karaoke-ready pitch data.

- convert_file() now calls _emit_vocal_sidecars() after writing the
  vocals XML (best-effort: a sidecar failure never breaks conversion,
  matching the notation-sidecar posture)
- lyrics sidecar is projected from the just-built vocals XML so timing
  stays in lockstep; the XML lyric convention's trailing '+' (join) is
  mapped to the spec 7.1 '-' (join) - a passthrough would have turned
  every joined word into a line break
- convert_vocal_track_to_pitch_sidecar() gains require_lyric=False for
  lyric-less melody tracks (pitch sidecar only)
- attach_vocal_sidecars_to_sloppak() added as the assembly-step helper
  (companion to attach_notation_to_sloppak): writes the sidecars into a
  directory-form pak and sets manifest lyrics/lyrics_source/vocal_pitch
  with no-clobber guards
- gp2rs_gpx registered in the spec-conformance READERS list

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: ChrisBeWithYou <chris@rifflarr.local>

lib/gp2rs_gpx.py

@@ -12,6 +12,7 @@ Both are called transparently by gp2rs.py when the file extension is .gpx.
 Do not call this module directly; use gp2rs.list_tracks / gp2rs.convert_file.
 """
 
+import json
 import logging
 import re
 import struct
@@ -1186,6 +1187,7 @@ def convert_vocal_track_to_pitch_sidecar(
     *,
     tempo_bpm: float = 120.0,
     audio_offset: float = 0.0,
+    require_lyric: bool = True,
 ) -> dict:
     """
     Extract per-syllable pitch from a GPX vocal track as a vocal_pitch.json dict.
@@ -1196,14 +1198,17 @@ def convert_vocal_track_to_pitch_sidecar(
 
         {"version": 1, "notes": [{"t": float, "d": float, "midi": int}, ...]}
 
-    This is complementary to convert_vocal_track() which produces arrangement XML.
+    This is complementary to convert_vocal_track() which produces arrangement
-    NOTE: nothing in this module calls this helper yet — convert_file() does not
+    XML. convert_file() calls both for every vocal track and writes the result
-    invoke it, so no vocal_pitch.json is emitted automatically. A caller wanting
+    as a ``<stem>.vocal_pitch.json`` sidecar next to the vocals XML (see
-    the pitch ribbon must call this itself and persist the returned dict (e.g.
+    _emit_vocal_sidecars); the sloppak assembly step then attaches it via
-    write it as vocal_pitch.json into the sloppak). When wiring vocals into a
+    attach_vocal_sidecars_to_sloppak.
-    sloppak, call both:
+
-        - convert_vocal_track() → vocals arrangement XML (karaoke highway)
+    ``require_lyric`` (default True) keeps the feedpak-spec §7.2 alignment:
-        - convert_vocal_track_to_pitch_sidecar() → vocal_pitch.json (pitch ribbon)
+    only beats carrying a lyric emit a note, so the pitch ribbon mirrors
+    lyrics.json token-for-token. Pass False for a lyric-less vocal track
+    (authored melody, no lyric text) to emit every pitched beat instead —
+    there are no lyric tokens to stay aligned with.
 
     Pitch source is the tab author's authored notes (exact), not AI audio
     analysis — so this is more accurate than pYIN/CREPE for well-authored tabs.
@@ -1258,13 +1263,15 @@ def convert_vocal_track_to_pitch_sidecar(
                         # Only emit notes that have a lyric — unvoiced beats
                         # (rests, instrumental fills) are excluded so the
                         # pitch ribbon stays aligned with lyric tokens.
+                        # (Relaxed via require_lyric=False for lyric-less
+                        # vocal tracks, where every pitched beat counts.)
                         lyric_el = beat_el.find('Lyrics')
                         has_lyric = (
                             lyric_el is not None
                             and lyric_el.find('Line') is not None
                             and (lyric_el.find('Line').text or '').strip()
                         )
-                        if not has_lyric:
+                        if require_lyric and not has_lyric:
                             voice_time += dur
                             continue
 
@@ -1682,6 +1689,26 @@ def convert_file(
                 raise ValueError(f"unsafe output filename from track name: {track['name']!r}")
             filepath.write_text(xml_str, encoding="utf-8")
             output_files.append(str(filepath))
+
+            # Vocal tracks additionally get karaoke sidecars next to the XML
+            # (`<stem>.lyrics.json` + `<stem>.vocal_pitch.json`, feedpak spec
+            # §7.1/§7.2) so the sloppak assembly step can attach the `lyrics` /
+            # `vocal_pitch` manifest keys without re-walking the GP file —
+            # same pattern as the keys notation sidecar below. Best-effort: a
+            # sidecar bug must never break the vocals XML conversion itself.
+            try:
+                _emit_vocal_sidecars(
+                    filepath, xml_str,
+                    root, track, raw_idx,
+                    masterbars, bars_by_id, voices_dict, beats_dict,
+                    notes_dict, rhythms_dict,
+                    tempo_bpm=tempo_bpm, audio_offset=audio_offset,
+                )
+            except Exception:
+                _log.exception(
+                    "gp2rs_gpx: vocal sidecar emission failed for track %r "
+                    "— vocals XML is unaffected", track['name'],
+                )
             continue
 
         # Iterate all masterbars and collect notes for this track
@@ -2403,6 +2430,195 @@ def _build_vocals_xml(
     return dom.toprettyxml(indent='  ', encoding=None)
 
 
+# ---------------------------------------------------------------------------
+# Vocal karaoke sidecars + manifest wiring (feedpak spec §7.1/§7.2)
+# Mirrors the gp2notation sidecar pattern: convert_file writes the payloads
+# next to the vocals XML (arrangement ids / the pak don't exist yet at convert
+# time), and the sloppak assembly step moves them into the pak root + manifest
+# via attach_vocal_sidecars_to_sloppak.
+# ---------------------------------------------------------------------------
+
+def lyrics_sidecar_path(xml_path: str | Path) -> Path:
+    """``Voice_Vocals.xml`` → ``Voice_Vocals.lyrics.json`` (next to the XML)."""
+    p = Path(xml_path)
+    return p.with_name(p.stem + ".lyrics.json")
+
+
+def vocal_pitch_sidecar_path(xml_path: str | Path) -> Path:
+    """``Voice_Vocals.xml`` → ``Voice_Vocals.vocal_pitch.json`` (next to the XML)."""
+    p = Path(xml_path)
+    return p.with_name(p.stem + ".vocal_pitch.json")
+
+
+def _vocals_xml_to_lyrics(xml_str: str) -> list[dict]:
+    """Project a ``<vocals>`` arrangement XML into the flat lyrics.json shape
+    (feedpak spec §7.1): ``[{"t": float, "d": float, "w": str}, ...]``.
+
+    Deriving from the XML (rather than re-walking the GP tree) guarantees the
+    two stay in lockstep — same tie extension, same rounding, same beats.
+
+    Suffix conversion: the XML lyric convention and feedpak disagree on ``+``.
+    In the vocals XML a trailing ``+`` means "connect to next token" (a join),
+    while feedpak ``+`` marks the last syllable of a LINE — so a pass-through
+    would turn every joined syllable into a line break. Joins map to feedpak's
+    trailing ``-`` instead; a trailing ``-`` already means the same thing in
+    both. Line-end ``+`` markers are never emitted: GP stores lyrics per beat
+    with no line structure, so there is nothing to derive them from.
+    """
+    try:
+        root = ET.fromstring(xml_str)
+    except ET.ParseError:
+        return []
+    lyrics: list[dict] = []
+    for v in root.iter('vocal'):
+        w = (v.get('lyric') or '').strip()
+        if w.endswith('+'):
+            w = w[:-1] + '-'
+        # A bare joiner token isn't a syllable (spec: suffixes ride on real
+        # syllables, never standalone entries) — skip it.
+        if not w or w in ('-', '+'):
+            continue
+        try:
+            t = float(v.get('time', ''))
+            d = float(v.get('length', ''))
+        except (TypeError, ValueError):
+            continue
+        lyrics.append({'t': round(t, 3), 'd': round(d, 3), 'w': w})
+    return lyrics
+
+
+def _emit_vocal_sidecars(
+    xml_path: Path,
+    xml_str: str,
+    root: ET.Element,
+    track: dict,
+    raw_idx: int,
+    masterbars: list,
+    bars_by_id: dict,
+    voices_dict: dict,
+    beats_dict: dict,
+    notes_dict: dict,
+    rhythms_dict: dict,
+    *,
+    tempo_bpm: float = 120.0,
+    audio_offset: float = 0.0,
+) -> list[Path]:
+    """Write the karaoke sidecars for one converted vocal track.
+
+    ``<stem>.lyrics.json`` — only when the track actually carries lyric text
+    (derived from the vocals XML just built, so timings match exactly).
+    ``<stem>.vocal_pitch.json`` — whenever the track has pitched beats. With
+    lyrics present the notes stay lyric-aligned (spec §7.2: one entry per
+    syllable); for a lyric-less melody track the lyric gate is dropped so the
+    authored pitch still ships.
+
+    Returns the sidecar paths written (possibly empty).
+    """
+    written: list[Path] = []
+
+    lyrics = _vocals_xml_to_lyrics(xml_str)
+    if lyrics:
+        side = lyrics_sidecar_path(xml_path)
+        side.write_text(json.dumps(lyrics, separators=(",", ":")),
+                        encoding="utf-8")
+        written.append(side)
+
+    pitch = convert_vocal_track_to_pitch_sidecar(
+        root, track, raw_idx,
+        masterbars, bars_by_id, voices_dict, beats_dict,
+        notes_dict, rhythms_dict,
+        tempo_bpm=tempo_bpm, audio_offset=audio_offset,
+        require_lyric=bool(lyrics),
+    )
+    if pitch.get('notes'):
+        side = vocal_pitch_sidecar_path(xml_path)
+        side.write_text(json.dumps(pitch, separators=(",", ":")),
+                        encoding="utf-8")
+        written.append(side)
+
+    return written
+
+
+def attach_vocal_sidecars_to_sloppak(
+    sloppak_dir: str | Path,
+    *,
+    lyrics: list | None = None,
+    vocal_pitch: dict | None = None,
+    lyrics_source: str = "authored",
+) -> list[Path]:
+    """Write ``lyrics.json`` / ``vocal_pitch.json`` into a directory-form
+    sloppak and point the top-level manifest ``lyrics`` / ``lyrics_source`` /
+    ``vocal_pitch`` keys at them (feedpak spec §7.1/§7.2).
+
+    Vocal companion to gp2notation.attach_notation_to_sloppak, with the same
+    manifest round-trip caveat (PyYAML ``safe_load`` + ``safe_dump`` — key
+    order survives, comments don't). GP-derived payloads are ``authored``
+    provenance, so no ``lyric_transcription`` / ``pitch_extraction`` blocks
+    are written (the spec reserves those for automated engines).
+
+    Never clobbers: a payload whose manifest key is already set (or whose
+    target file already exists) is skipped, so a pak that already carries
+    lyrics/pitch — hand-edited or machine-extracted — is left alone.
+    Raises ``ValueError`` on a malformed payload, an unknown
+    ``lyrics_source``, or a manifest that isn't a mapping. Returns the paths
+    actually written.
+    """
+    import yaml
+
+    if lyrics_source not in ("authored", "transcribed", "user"):
+        raise ValueError(
+            f"lyrics_source must be authored/transcribed/user, got {lyrics_source!r}")
+    if lyrics is not None and not (
+        isinstance(lyrics, list) and all(
+            isinstance(e, dict)
+            and isinstance(e.get('w'), str)
+            and isinstance(e.get('t'), (int, float))
+            and isinstance(e.get('d'), (int, float))
+            for e in lyrics
+        )
+    ):
+        raise ValueError("lyrics must be a list of {t, d, w} syllable dicts")
+    if vocal_pitch is not None and not (
+        isinstance(vocal_pitch, dict)
+        and isinstance(vocal_pitch.get('notes'), list)
+    ):
+        raise ValueError("vocal_pitch must be a dict with a `notes` list")
+
+    pak = Path(sloppak_dir)
+    manifest_path = pak / "manifest.yaml"
+    manifest = yaml.safe_load(manifest_path.read_text(encoding="utf-8"))
+    if not isinstance(manifest, dict):
+        raise ValueError(f"{manifest_path} is not a mapping")
+
+    written: list[Path] = []
+
+    if lyrics and not manifest.get("lyrics") and not (pak / "lyrics.json").exists():
+        (pak / "lyrics.json").write_text(
+            json.dumps(lyrics, separators=(",", ":")), encoding="utf-8")
+        manifest["lyrics"] = "lyrics.json"
+        manifest["lyrics_source"] = lyrics_source
+        written.append(pak / "lyrics.json")
+
+    if (vocal_pitch and vocal_pitch.get("notes")
+            and not manifest.get("vocal_pitch")
+            and not (pak / "vocal_pitch.json").exists()):
+        (pak / "vocal_pitch.json").write_text(
+            json.dumps(vocal_pitch, separators=(",", ":")), encoding="utf-8")
+        manifest["vocal_pitch"] = "vocal_pitch.json"
+        written.append(pak / "vocal_pitch.json")
+
+    if written:
+        # Stamp the format version while we're rewriting the manifest (spec
+        # §4), without downgrading an existing declared version.
+        from sloppak import FEEDPAK_VERSION
+        manifest.setdefault("feedpak_version", FEEDPAK_VERSION)
+        manifest_path.write_text(
+            yaml.safe_dump(manifest, sort_keys=False, allow_unicode=True),
+            encoding="utf-8",
+        )
+    return written
+
+
 def _gpx_tuning(track: dict) -> list[int]:
     """Compute RS tuning offsets (semitones from standard) from GPX string pitches."""
     from gp2rs import STANDARD_TUNING_GUITAR, STANDARD_TUNING_BASS

tests/test_gp2rs_gpx.py

@@ -7,6 +7,7 @@ the PR; here we pin the input-validation guards and the conversion helpers
 that are easy to drive without a fixture.
 """
 
+import json
 import struct
 import xml.etree.ElementTree as ET
 
@@ -29,6 +30,10 @@ from gp2rs_gpx import (
     _GPX_MAX_DECOMPRESSED,
     _find_piano_pairs,
     convert_vocal_track_to_pitch_sidecar,
+    _vocals_xml_to_lyrics,
+    attach_vocal_sidecars_to_sloppak,
+    lyrics_sidecar_path,
+    vocal_pitch_sidecar_path,
     _collect_tone_events,
     _inject_tones,
     _resolve_pending_slides,
@@ -386,6 +391,192 @@ def test_vocal_pitch_sidecar_skips_beat_without_lyric():
     assert out == {"version": 1, "notes": []}
 
 
+def test_vocal_pitch_sidecar_require_lyric_false_emits_melody():
+    # Lyric-less vocal track: with the gate relaxed the authored pitch still
+    # ships (there are no lyric tokens to stay aligned with).
+    out = convert_vocal_track_to_pitch_sidecar(
+        **_vocal_sidecar_args(with_lyric=False), require_lyric=False)
+    assert out == {"version": 1, "notes": [{"t": 0.0, "d": 0.5, "midi": 60}]}
+
+
+# ── _vocals_xml_to_lyrics ───────────────────────────────────────────────────
+
+def test_vocals_xml_to_lyrics_shape_and_suffixes():
+    xml = (
+        '<vocals count="4">'
+        '<vocal time="0.000" note="60" length="0.500" lyric="Hel-"/>'
+        '<vocal time="0.500" note="62" length="0.500" lyric="lo"/>'
+        '<vocal time="1.000" note="64" length="0.250" lyric="sing+"/>'
+        '<vocal time="1.250" note="64" length="0.250" lyric="ing"/>'
+        '</vocals>'
+    )
+    out = _vocals_xml_to_lyrics(xml)
+    assert out == [
+        # "-" means the same join in both conventions — passed through.
+        {"t": 0.0, "d": 0.5, "w": "Hel-"},
+        {"t": 0.5, "d": 0.5, "w": "lo"},
+        # XML "+" is a JOIN; feedpak "+" is a LINE END — joins become "-".
+        {"t": 1.0, "d": 0.25, "w": "sing-"},
+        {"t": 1.25, "d": 0.25, "w": "ing"},
+    ]
+
+
+def test_vocals_xml_to_lyrics_skips_bare_joiners_and_bad_xml():
+    xml = (
+        '<vocals count="2">'
+        '<vocal time="0.000" note="0" length="0.500" lyric="+"/>'
+        '<vocal time="0.500" note="60" length="0.500" lyric="la"/>'
+        '</vocals>'
+    )
+    assert _vocals_xml_to_lyrics(xml) == [{"t": 0.5, "d": 0.5, "w": "la"}]
+    assert _vocals_xml_to_lyrics("not xml <<<") == []
+
+
+# ── convert_file end-to-end: vocal karaoke sidecars ─────────────────────────
+# A vocal track must emit `<stem>.lyrics.json` + `<stem>.vocal_pitch.json`
+# next to the vocals XML; non-vocal tracks must not; a lyric-less vocal track
+# emits the pitch sidecar only.
+
+_GPIF_VOCAL = """
+<GPIF>
+  <Score><Title>T</Title><Artist>A</Artist></Score>
+  <Tracks>
+    <Track id="0"><Name>Vocals</Name>
+      <Property name="Tuning"><Pitches>60</Pitches></Property></Track>
+  </Tracks>
+  <MasterBars><MasterBar><Time>4/4</Time><Bars>0</Bars></MasterBar></MasterBars>
+  <Bars><Bar id="0"><Voices>0</Voices></Bar></Bars>
+  <Voices><Voice id="0"><Beats>0 1</Beats></Voice></Voices>
+  <Beats>
+    <Beat id="0"><Rhythm ref="r0"/><Lyrics><Line>Hel-</Line></Lyrics><Notes>0</Notes></Beat>
+    <Beat id="1"><Rhythm ref="r0"/><Lyrics><Line>lo</Line></Lyrics><Notes>1</Notes></Beat>
+  </Beats>
+  <Notes>
+    <Note id="0">
+      <Property name="String"><String>0</String></Property>
+      <Property name="Fret"><Fret>0</Fret></Property></Note>
+    <Note id="1">
+      <Property name="String"><String>0</String></Property>
+      <Property name="Fret"><Fret>2</Fret></Property></Note>
+  </Notes>
+  <Rhythms><Rhythm id="r0"><NoteValue>Quarter</NoteValue></Rhythm></Rhythms>
+</GPIF>
+"""
+
+# Same melody, no <Lyrics> anywhere.
+_GPIF_VOCAL_NO_LYRICS = _GPIF_VOCAL.replace(
+    "<Lyrics><Line>Hel-</Line></Lyrics>", "").replace(
+    "<Lyrics><Line>lo</Line></Lyrics>", "")
+
+
+def test_convert_file_vocal_track_emits_both_sidecars(tmp_path, monkeypatch):
+    monkeypatch.setattr(gp2rs_gpx, "_load_gpif",
+                        lambda _p: ET.fromstring(_GPIF_VOCAL))
+    out_files = convert_file("dummy.gpx", str(tmp_path), track_indices=[0])
+    assert len(out_files) == 1
+    assert ET.parse(out_files[0]).getroot().tag == "vocals"
+
+    # lyrics.json sidecar: flat [{t, d, w}] (spec §7.1), timings from the XML.
+    lyr = json.loads(lyrics_sidecar_path(out_files[0]).read_text(encoding="utf-8"))
+    assert lyr == [
+        {"t": 0.0, "d": 0.5, "w": "Hel-"},
+        {"t": 0.5, "d": 0.5, "w": "lo"},
+    ]
+
+    # vocal_pitch.json sidecar: {version, notes:[{t, d, midi}]} (spec §7.2),
+    # lyric-aligned (one note per syllable) at the authored pitches.
+    pitch = json.loads(vocal_pitch_sidecar_path(out_files[0]).read_text(encoding="utf-8"))
+    assert pitch == {"version": 1, "notes": [
+        {"t": 0.0, "d": 0.5, "midi": 60},
+        {"t": 0.5, "d": 0.5, "midi": 62},
+    ]}
+
+
+def test_convert_file_no_vocal_track_no_sidecars(tmp_path, monkeypatch):
+    monkeypatch.setattr(gp2rs_gpx, "_load_gpif",
+                        lambda _p: ET.fromstring(_GPIF_GUITAR_ASCENDING))
+    convert_file("dummy.gp", str(tmp_path),
+                 track_indices=[0], arrangement_names={0: "Lead"})
+    assert not list(tmp_path.glob("*.lyrics.json"))
+    assert not list(tmp_path.glob("*.vocal_pitch.json"))
+
+
+def test_convert_file_lyricless_vocal_track_pitch_sidecar_only(tmp_path, monkeypatch):
+    monkeypatch.setattr(gp2rs_gpx, "_load_gpif",
+                        lambda _p: ET.fromstring(_GPIF_VOCAL_NO_LYRICS))
+    out_files = convert_file("dummy.gpx", str(tmp_path), track_indices=[0])
+    assert len(out_files) == 1
+    # No lyric text anywhere -> no lyrics.json; the authored melody still
+    # ships as vocal_pitch.json (lyric gate relaxed for lyric-less tracks).
+    assert not lyrics_sidecar_path(out_files[0]).exists()
+    pitch = json.loads(vocal_pitch_sidecar_path(out_files[0]).read_text(encoding="utf-8"))
+    assert pitch == {"version": 1, "notes": [
+        {"t": 0.0, "d": 0.5, "midi": 60},
+        {"t": 0.5, "d": 0.5, "midi": 62},
+    ]}
+
+
+# ── attach_vocal_sidecars_to_sloppak ────────────────────────────────────────
+
+_LYRICS_PAYLOAD = [{"t": 0.0, "d": 0.5, "w": "Hel-"}, {"t": 0.5, "d": 0.5, "w": "lo"}]
+_PITCH_PAYLOAD = {"version": 1, "notes": [{"t": 0.0, "d": 0.5, "midi": 60}]}
+
+
+def _make_pak(tmp_path, manifest: dict):
+    import yaml
+    pak = tmp_path / "pak"
+    pak.mkdir()
+    (pak / "manifest.yaml").write_text(
+        yaml.safe_dump(manifest, sort_keys=False), encoding="utf-8")
+    return pak
+
+
+def test_attach_vocal_sidecars_writes_files_and_manifest(tmp_path):
+    import yaml
+    pak = _make_pak(tmp_path, {"title": "T", "arrangements": []})
+    written = attach_vocal_sidecars_to_sloppak(
+        pak, lyrics=_LYRICS_PAYLOAD, vocal_pitch=_PITCH_PAYLOAD)
+    assert written == [pak / "lyrics.json", pak / "vocal_pitch.json"]
+    assert json.loads((pak / "lyrics.json").read_text(encoding="utf-8")) == _LYRICS_PAYLOAD
+    assert json.loads((pak / "vocal_pitch.json").read_text(encoding="utf-8")) == _PITCH_PAYLOAD
+    manifest = yaml.safe_load((pak / "manifest.yaml").read_text(encoding="utf-8"))
+    assert manifest["lyrics"] == "lyrics.json"
+    assert manifest["lyrics_source"] == "authored"      # GP tab = authored chart
+    assert manifest["vocal_pitch"] == "vocal_pitch.json"
+    # No automated-engine provenance for authored payloads (spec §7.1.1/§7.2.1).
+    assert "lyric_transcription" not in manifest
+    assert "pitch_extraction" not in manifest
+    assert "feedpak_version" in manifest
+
+
+def test_attach_vocal_sidecars_never_clobbers(tmp_path):
+    import yaml
+    pak = _make_pak(tmp_path, {
+        "title": "T",
+        "lyrics": "existing_lyrics.json",
+        "lyrics_source": "user",
+    })
+    written = attach_vocal_sidecars_to_sloppak(
+        pak, lyrics=_LYRICS_PAYLOAD, vocal_pitch=_PITCH_PAYLOAD)
+    # lyrics already claimed by the manifest -> skipped entirely; pitch is new.
+    assert written == [pak / "vocal_pitch.json"]
+    assert not (pak / "lyrics.json").exists()
+    manifest = yaml.safe_load((pak / "manifest.yaml").read_text(encoding="utf-8"))
+    assert manifest["lyrics"] == "existing_lyrics.json"
+    assert manifest["lyrics_source"] == "user"
+
+
+def test_attach_vocal_sidecars_rejects_bad_payloads(tmp_path):
+    pak = _make_pak(tmp_path, {"title": "T"})
+    with pytest.raises(ValueError):
+        attach_vocal_sidecars_to_sloppak(pak, lyrics=[{"t": 0.0}])   # missing d/w
+    with pytest.raises(ValueError):
+        attach_vocal_sidecars_to_sloppak(pak, vocal_pitch={"version": 1})  # no notes
+    with pytest.raises(ValueError):
+        attach_vocal_sidecars_to_sloppak(
+            pak, lyrics=_LYRICS_PAYLOAD, lyrics_source="whisperx")  # not spec enum
+
+
 # ── _collect_tone_events ────────────────────────────────────────────────────
 
 def _tone_args(banks, tempo_map=((0, 120.0),)):

tools/check_spec_conformance.py

@@ -58,6 +58,7 @@ READERS = [
     "lib/enrichment.py",
     "lib/songmeta.py",
     "lib/gp2notation.py",        # rewrites manifest.yaml; stamps feedpak_version
+    "lib/gp2rs_gpx.py",          # attach_vocal_sidecars_to_sloppak: lyrics/vocal_pitch keys
     "lib/routers/ws_highway.py", # reads `authors` off a feedpak manifest
     "lib/routers/chart.py",      # Get-info panel: binds `m = load_manifest(...)`
     "lib/routers/song.py",       # enrichment gap-fill: reads the manifest directly