Two architectural cleanups on top of the download engine refactor.
(1) Shared dataclasses move to neutral plugin package.
TrackResult, AlbumResult, DownloadStatus, SearchResult lived in
core/soulseek_client.py for historical reasons — every other plugin
imported them from the soulseek module just to satisfy the contract,
coupling 8 clients to a sibling source for type imports only. Moved
them to the new core/download_plugins/types.py module and updated all
14 import sites across the deezer/hifi/lidarr/qobuz/soundcloud/tidal/
youtube clients, the engine, matching engine, redownload helper, and
tests. Clean break, no backward-compat re-export.
(2) web_server.py boots the orchestrator via the singleton factory.
After construction it now calls set_download_orchestrator(...) so
get_download_orchestrator() returns the same instance the global
handle points at instead of lazily building a separate orchestrator.
Matches the get_metadata_engine() pattern.
Cin's review feedback: the plugin contract was discoverable only
from the registry, not from the client files themselves. Reading
`youtube_client.py` cold gave no signal that the class participates
in the DownloadSourcePlugin contract.
Every download client class now inherits DownloadSourcePlugin
explicitly:
- SoulseekClient(DownloadSourcePlugin)
- YouTubeClient(DownloadSourcePlugin)
- TidalDownloadClient(DownloadSourcePlugin)
- QobuzClient(DownloadSourcePlugin)
- HiFiClient(DownloadSourcePlugin)
- DeezerDownloadClient(DownloadSourcePlugin)
- SoundcloudClient(DownloadSourcePlugin)
- LidarrDownloadClient(DownloadSourcePlugin)
Adjustments:
- core/download_plugins/base.py — moved TrackResult/AlbumResult/
DownloadStatus imports under TYPE_CHECKING since they're only
used in type annotations. Without this, clients inheriting the
contract create a circular import.
- core/download_plugins/__init__.py — drops DownloadPluginRegistry
re-export. Importing the package no longer triggers the registry's
eager client imports (which would also be circular for clients
that import from the package). Callers that need the registry
import it directly: `from core.download_plugins.registry import
DownloadPluginRegistry`.
Suite still green (335 download tests).
`core/download_plugins/` defines the canonical interface every
download source must satisfy and the registry that holds them.
Single source of truth replacing the orchestrator's hardcoded
`[self.soulseek, self.youtube, ...]` lists scattered across 6+
dispatch sites.
Pure additive — no consumers wired through the registry yet.
