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/src/rehearsalhub/db/models.py

@@ -232,6 +232,8 @@ class AudioVersion(Base):
     nc_file_etag: Mapped[Optional[str]] = mapped_column(String(255))
     cdn_hls_base: Mapped[Optional[str]] = mapped_column(Text)
     waveform_url: Mapped[Optional[str]] = mapped_column(Text)
+    waveform_peaks: Mapped[Optional[list]] = mapped_column(JSONB)
+    waveform_peaks_mini: Mapped[Optional[list]] = mapped_column(JSONB)
     duration_ms: Mapped[Optional[int]] = mapped_column(Integer)
     format: Mapped[Optional[str]] = mapped_column(String(10))
     file_size_bytes: Mapped[Optional[int]] = mapped_column(BigInteger)

api/src/rehearsalhub/routers/versions.py

@@ -180,49 +180,27 @@ async def create_version(
 @router.get("/versions/{version_id}/waveform")
 async def get_waveform(
     version_id: uuid.UUID,
+    resolution: str = Query("full", pattern="^(full|mini)$"),
     session: AsyncSession = Depends(get_session),
     current_member: Member = Depends(get_current_member),
 ) -> Any:
+    """Return pre-computed waveform peaks from the database.
+
+    - `resolution=full` (default): 500-point peaks for the WaveSurfer player
+    - `resolution=mini`: 100-point peaks for the library overview thumbnail
+    """
     version, _ = await _get_version_and_assert_band_membership(version_id, session, current_member)
-    if not version.waveform_url:
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Waveform not ready")
 
-    # Use the uploader's NC credentials — invited members may not have NC configured
-    uploader: Member | None = None
-    if version.uploaded_by:
-        uploader = await MemberRepository(session).get_by_id(version.uploaded_by)
-    storage = NextcloudClient.for_member(uploader) if uploader else NextcloudClient.for_member(current_member)
-    if storage is None:
-        raise HTTPException(
-            status_code=status.HTTP_403_FORBIDDEN,
-            detail="No storage provider configured for this account"
-        )
-    try:
-        data = await _download_with_retry(storage, version.waveform_url)
-    except httpx.ConnectError:
-        raise HTTPException(
-            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-            detail="Storage service unavailable."
-        )
-    except httpx.HTTPStatusError as e:
-        if e.response.status_code == 404:
-            raise HTTPException(
-                status_code=status.HTTP_404_NOT_FOUND,
-                detail="Waveform file not found in storage."
-            )
-        else:
-            raise HTTPException(
-                status_code=status.HTTP_502_BAD_GATEWAY,
-                detail="Storage returned an error."
-            )
-    except Exception:
-        raise HTTPException(
-            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="Failed to fetch waveform."
-        )
-    import json
+    if resolution == "mini":
+        peaks = version.waveform_peaks_mini
+        if peaks is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Mini waveform not ready")
+    else:
+        peaks = version.waveform_peaks
+        if peaks is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Waveform not ready")
 
-    return json.loads(data)
+    return {"version": 2, "channels": 1, "length": len(peaks), "data": peaks}
 
 
 @router.get("/versions/{version_id}/stream")

api/src/rehearsalhub/schemas/audio_version.py

@@ -22,6 +22,8 @@ class AudioVersionRead(BaseModel):
     nc_file_etag: str | None = None
     cdn_hls_base: str | None = None
     waveform_url: str | None = None
+    waveform_peaks: list[float] | None = None
+    waveform_peaks_mini: list[float] | None = None
     duration_ms: int | None = None
     format: str | None = None
     file_size_bytes: int | None = None