feat(waveform): precompute and store peaks in DB for instant rendering

Store waveform peaks inline in audio_versions (JSONB columns) so WaveSurfer
can render the waveform immediately on page load without waiting for audio
decode. Adds a 100-point mini-waveform for version selector thumbnails.

Backend:
- Migration 0006: adds waveform_peaks and waveform_peaks_mini JSONB columns
- Worker generates both resolutions (500-pt full, 100-pt mini) during transcode
  and stores them directly in DB — replaces file-based waveform_url approach
- AudioVersionRead schema exposes both fields inline (no extra HTTP round-trip)
- GET /versions/{id}/waveform reads from DB; adds ?resolution=mini support

Frontend:
- audioService.initialize() accepts peaks and calls ws.load(url, Float32Array)
  so waveform renders instantly without audio decode
- useWaveform hook threads peaks option through to audioService
- PlayerPanel passes waveform_peaks from the active version to the hook
- New MiniWaveform SVG component (no WaveSurfer) renders mini peaks in the
  version selector buttons

Fix: docker-compose.dev.yml now runs alembic upgrade head before starting
the API server, so a fresh volume gets the full schema automatically.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/tests/unit/test_waveform_endpoint.py

@@ -0,0 +1,120 @@
+"""Unit tests for GET /versions/{id}/waveform endpoint — reads peaks from DB."""
+
+import uuid
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from rehearsalhub.db.models import AudioVersion, Member, Song
+
+
+def _make_member() -> MagicMock:
+    m = MagicMock(spec=Member)
+    m.id = uuid.uuid4()
+    m.nc_url = "http://nc.test"
+    m.nc_username = "user"
+    m.nc_password = "pass"
+    return m
+
+
+def _make_version(peaks=None, peaks_mini=None, has_waveform_url=False) -> MagicMock:
+    v = MagicMock(spec=AudioVersion)
+    v.id = uuid.uuid4()
+    v.song_id = uuid.uuid4()
+    v.uploaded_by = None
+    v.waveform_url = "waveforms/test.json" if has_waveform_url else None
+    v.waveform_peaks = peaks
+    v.waveform_peaks_mini = peaks_mini
+    v.cdn_hls_base = None
+    v.nc_file_path = "/bands/test/v1.wav"
+    return v
+
+
+def _make_song(band_id: uuid.UUID) -> MagicMock:
+    s = MagicMock(spec=Song)
+    s.id = uuid.uuid4()
+    s.band_id = band_id
+    return s
+
+
+@pytest.mark.asyncio
+async def test_waveform_returns_full_peaks_from_db(mock_session):
+    """GET /versions/{id}/waveform returns 500-point peaks from DB column."""
+    from rehearsalhub.routers.versions import get_waveform
+
+    peaks = [float(i) / 500 for i in range(500)]
+    version = _make_version(peaks=peaks)
+    member = _make_member()
+    band_id = uuid.uuid4()
+    song = _make_song(band_id)
+
+    with (
+        patch("rehearsalhub.routers.versions._get_version_and_assert_band_membership",
+              return_value=(version, song)),
+    ):
+        result = await get_waveform(version_id=version.id, session=mock_session, current_member=member)
+
+    assert result["data"] == peaks
+    assert result["length"] == 500
+    assert "mini" not in result
+
+
+@pytest.mark.asyncio
+async def test_waveform_returns_mini_peaks_with_resolution_param(mock_session):
+    """GET /versions/{id}/waveform?resolution=mini returns 100-point peaks."""
+    from rehearsalhub.routers.versions import get_waveform
+
+    peaks_mini = [float(i) / 100 for i in range(100)]
+    version = _make_version(peaks=[0.5] * 500, peaks_mini=peaks_mini)
+    member = _make_member()
+    band_id = uuid.uuid4()
+    song = _make_song(band_id)
+
+    with (
+        patch("rehearsalhub.routers.versions._get_version_and_assert_band_membership",
+              return_value=(version, song)),
+    ):
+        result = await get_waveform(version_id=version.id, session=mock_session, current_member=member, resolution="mini")
+
+    assert result["data"] == peaks_mini
+    assert result["length"] == 100
+
+
+@pytest.mark.asyncio
+async def test_waveform_404_when_no_peaks_in_db(mock_session):
+    """GET /versions/{id}/waveform returns 404 when no peaks stored yet."""
+    from fastapi import HTTPException
+    from rehearsalhub.routers.versions import get_waveform
+
+    version = _make_version(peaks=None, peaks_mini=None)
+    member = _make_member()
+    song = _make_song(uuid.uuid4())
+
+    with (
+        patch("rehearsalhub.routers.versions._get_version_and_assert_band_membership",
+              return_value=(version, song)),
+    ):
+        with pytest.raises(HTTPException) as exc_info:
+            await get_waveform(version_id=version.id, session=mock_session, current_member=member)
+
+    assert exc_info.value.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_waveform_mini_404_when_no_mini_peaks(mock_session):
+    """GET /versions/{id}/waveform?resolution=mini returns 404 when no mini peaks stored."""
+    from fastapi import HTTPException
+    from rehearsalhub.routers.versions import get_waveform
+
+    version = _make_version(peaks=[0.5] * 500, peaks_mini=None)
+    member = _make_member()
+    song = _make_song(uuid.uuid4())
+
+    with (
+        patch("rehearsalhub.routers.versions._get_version_and_assert_band_membership",
+              return_value=(version, song)),
+    ):
+        with pytest.raises(HTTPException) as exc_info:
+            await get_waveform(version_id=version.id, session=mock_session, current_member=member, resolution="mini")
+
+    assert exc_info.value.status_code == 404