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_versions_list_peaks.py

@@ -0,0 +1,38 @@
+"""Confirm that list_versions returns waveform_peaks inline (no extra request needed)."""
+
+import uuid
+from datetime import datetime, timezone
+from unittest.mock import MagicMock
+
+from rehearsalhub.db.models import AudioVersion
+from rehearsalhub.schemas.audio_version import AudioVersionRead
+
+
+def test_audio_version_read_includes_peaks_in_list_serialization():
+    """AudioVersionRead (used by list_versions) serializes waveform_peaks inline."""
+    peaks = [0.1, 0.5, 0.9]
+    mini = [0.3, 0.7]
+
+    v = MagicMock(spec=AudioVersion)
+    v.id = uuid.uuid4()
+    v.song_id = uuid.uuid4()
+    v.version_number = 1
+    v.label = None
+    v.nc_file_path = "/test/v1.wav"
+    v.nc_file_etag = "etag"
+    v.cdn_hls_base = None
+    v.waveform_url = None
+    v.waveform_peaks = peaks
+    v.waveform_peaks_mini = mini
+    v.duration_ms = 3000
+    v.format = "wav"
+    v.file_size_bytes = 512
+    v.analysis_status = "done"
+    v.uploaded_by = None
+    v.uploaded_at = datetime.now(timezone.utc)
+
+    schema = AudioVersionRead.model_validate(v)
+    serialized = schema.model_dump()
+
+    assert serialized["waveform_peaks"] == peaks
+    assert serialized["waveform_peaks_mini"] == mini