fix(lidarr): send the artist add's monitor choice in addOptions (#5239)

ArtistResource has no top-level `monitor`. Lidarr reads the choice from
AddOptions (AddArtistOptions, a MonitoringOptions), so the "all"/"future"
we sent there was dropped on deserialisation. AddOptions.Monitor stayed
Unknown, and AlbumMonitoredService.SetAlbumMonitoredStatus returns early
on Unknown. The request's monitoring was never applied.

Send monitor and monitored inside addOptions with searchForMissingAlbums,
the shape Lidarr's getNewArtist.js posts, and set monitorNewItems "all"
explicitly: both choices mean new releases are watched.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/lidarr/types.go

@@ -57,7 +57,7 @@ type AddArtistParams struct {
 	QualityProfileID  int
 	MetadataProfileID int
 	RootFolderPath    string
-	MonitorAll        bool // true => monitor="all"; false => "future"
+	MonitorAll        bool // true => addOptions.monitor="all"; false => "future"
 }
 
 // AddAlbumParams identify the album to add and carry the settings Lidarr