Publish download events from PollDownloadWorker to event stream

PollDownloadWorker now publishes status/result/error events to both the
EventBus (for live UI updates via SubscribeEvents) and AlbumEventRepository
(for DB persistence and replay on reconnect).

- Add AlbumID, Quality, WorkflowRunID to PollDownloadArgs
- Add EventBus and AlbumEvents fields to PollDownloadWorker
- Publish status events with progress % on each poll tick
- Publish result event on download completion
- Publish error events on torrent failure
- Thread workflowRunID through saveTorrentAndDownload for event correlation
- RecoverOrphanedDownloads populates AlbumID/Quality from download record

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/claude-agent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/monitor_workflow.go

@@ -417,7 +417,7 @@ func (w *monitorWorkflow) run(ctx context.Context) error {
 	}
 	if dbAlbum != nil {
 		w.publisher.SetAlbumID(dbAlbum.ID)
-		w.service.saveTorrentAndDownload(ctx, dbAlbum.ID, best)
+		w.service.saveTorrentAndDownload(ctx, dbAlbum.ID, w.workflowRunID, best)
 	} else {
 		log.Warn().Str("album_id", w.req.AlbumId).Msg("album not in DB after persist attempt, skipping torrent/download persistence")
 	}

internal/service.go

@@ -589,7 +589,7 @@ func (service *MusicAgregatorService) MonitorAlbum(ctx context.Context, req *pb.
 		dbAlbum, _ = service.metadata.GetAlbumByExternalID(ctx, album.GetId())
 	}
 	if dbAlbum != nil {
-		service.saveTorrentAndDownload(ctx, dbAlbum.ID, best)
+		service.saveTorrentAndDownload(ctx, dbAlbum.ID, "", best)
 	} else {
 		log.Warn().Str("album_id", req.GetAlbumId()).Msg("album not in DB after persist attempt, skipping torrent/download persistence")
 	}
@@ -840,7 +840,7 @@ func (service *MusicAgregatorService) addToTorrentClient(best parsedItem) error
 	return nil
 }
 
-func (service *MusicAgregatorService) saveTorrentAndDownload(ctx context.Context, dbAlbumID string, best parsedItem) {
+func (service *MusicAgregatorService) saveTorrentAndDownload(ctx context.Context, dbAlbumID string, workflowRunID string, best parsedItem) {
 	quality := normalizeQuality(pb.QualityType_QUALITY_UNSPECIFIED, best.rel.BitDepth, best.rel.SampleRate)
 
 	dbTorrent := &database.Torrent{
@@ -898,6 +898,9 @@ func (service *MusicAgregatorService) saveTorrentAndDownload(ctx context.Context
 			DownloadID:    download.ID,
 			TorrentHash:   best.rel.InfoHash,
 			CheckInterval: 30 * time.Second,
+			AlbumID:       dbAlbumID,
+			Quality:       quality,
+			WorkflowRunID: workflowRunID,
 		}, &river.InsertOpts{
 			ScheduledAt: time.Now().Add(30 * time.Second),
 		})

internal/workers/poll_download.go

@@ -2,6 +2,7 @@ package workers
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"github.com/jackc/pgx/v5"
@@ -10,6 +11,7 @@ import (
 
 	"homelab.lan/music-agregator/internal/analysis"
 	"homelab.lan/music-agregator/internal/database"
+	"homelab.lan/music-agregator/internal/eventbus"
 	"homelab.lan/music-agregator/internal/metadata"
 	"homelab.lan/music-agregator/internal/musicfs"
 	"homelab.lan/music-agregator/internal/torrent"
@@ -19,24 +21,29 @@ type PollDownloadArgs struct {
 	DownloadID    string        `json:"download_id"`
 	TorrentHash   string        `json:"torrent_hash"`
 	CheckInterval time.Duration `json:"check_interval"`
+	AlbumID       string        `json:"album_id"`
+	Quality       string        `json:"quality"`
+	WorkflowRunID string        `json:"workflow_run_id"`
 }
 
 func (PollDownloadArgs) Kind() string { return "poll_download" }
 
 type PollDownloadWorker struct {
 	river.WorkerDefaults[PollDownloadArgs]
-	TorrentClient    torrent.TorrentClient
+	TorrentClient     torrent.TorrentClient
-	Downloads        *database.DownloadRepository
+	Downloads         *database.DownloadRepository
-	DownloadFiles    *database.DownloadFileRepository
+	DownloadFiles     *database.DownloadFileRepository
-	AlbumReleases    *database.AlbumReleaseRepository
+	AlbumReleases     *database.AlbumReleaseRepository
-	TrackReleases    *database.TrackReleaseRepository
+	TrackReleases     *database.TrackReleaseRepository
-	RiverClient      *river.Client[pgx.Tx]
+	RiverClient       *river.Client[pgx.Tx]
-	PathMapper       *torrent.PathMapper
+	PathMapper        *torrent.PathMapper
-	Analyzer         *analysis.ReleaseAnalyzer
+	Analyzer          *analysis.ReleaseAnalyzer
-	MusicFSClient    *musicfs.Client
+	MusicFSClient     *musicfs.Client
-	MusicFSOriginID  string
+	MusicFSOriginID   string
 	MusicFSOriginRoot string
-	MetadataService  *metadata.MetadataService
+	MetadataService   *metadata.MetadataService
+	EventBus          *eventbus.EventBus
+	AlbumEvents       *database.AlbumEventRepository
 }
 
 func (w *PollDownloadWorker) Work(ctx context.Context, job *river.Job[PollDownloadArgs]) error {
@@ -53,6 +60,7 @@ func (w *PollDownloadWorker) Work(ctx context.Context, job *river.Job[PollDownlo
 	if len(results) == 0 {
 		log.Warn().Str("hash", args.TorrentHash).Msg("torrent not found in client, marking failed")
 		w.Downloads.SetFailed(ctx, args.DownloadID, "torrent not found in client")
+		w.publishEvent(ctx, args, "error", "", "torrent not found in client")
 		return nil
 	}
 
@@ -65,6 +73,7 @@ func (w *PollDownloadWorker) Work(ctx context.Context, job *river.Job[PollDownlo
 	case t.State == "error":
 		log.Warn().Str("hash", args.TorrentHash).Str("state", t.State).Msg("torrent in error state")
 		w.Downloads.SetFailed(ctx, args.DownloadID, "torrent error state")
+		w.publishEvent(ctx, args, "error", "", "torrent error state")
 		return nil
 
 	default:
@@ -74,6 +83,8 @@ func (w *PollDownloadWorker) Work(ctx context.Context, job *river.Job[PollDownlo
 			Float64("progress", t.Progress*100).
 			Int64("dlspeed", t.DlSpeed).
 			Msg("download in progress")
+		w.publishEvent(ctx, args, "status", "",
+			fmt.Sprintf("Downloading: %.1f%% ↓%s", t.Progress*100, formatSpeed(t.DlSpeed)))
 		return w.reschedule(ctx, args)
 	}
 }
@@ -127,6 +138,8 @@ func (w *PollDownloadWorker) onCompleted(ctx context.Context, args PollDownloadA
 		w.syncAndEnrichMusicFS(ctx, args, contentPath)
 	}
 
+	w.publishEvent(ctx, args, "result", "MONITOR_STEP_COMPLETE", "Download completed")
+
 	return nil
 }
 
@@ -207,6 +220,8 @@ func (w *PollDownloadWorker) RecoverOrphanedDownloads(ctx context.Context) {
 			DownloadID:    d.ID,
 			TorrentHash:   d.QbitHash,
 			CheckInterval: 30 * time.Second,
+			AlbumID:       d.AlbumID,
+			Quality:       d.Quality,
 		}, &river.InsertOpts{
 			ScheduledAt: time.Now().Add(5 * time.Second),
 			UniqueOpts: river.UniqueOpts{
@@ -220,3 +235,48 @@ func (w *PollDownloadWorker) RecoverOrphanedDownloads(ctx context.Context) {
 		}
 	}
 }
+
+func (w *PollDownloadWorker) publishEvent(ctx context.Context, args PollDownloadArgs, eventType, step, message string) {
+	if w.EventBus == nil {
+		return
+	}
+
+	topic := args.AlbumID + ":" + args.Quality
+
+	var seq int64
+	if w.AlbumEvents != nil && args.AlbumID != "" {
+		event := &database.AlbumEvent{
+			WorkflowRunID: args.WorkflowRunID,
+			AlbumID:       args.AlbumID,
+			EventType:     eventType,
+			Step:          step,
+			Message:       message,
+		}
+		if err := w.AlbumEvents.Create(ctx, event); err != nil {
+			log.Error().Err(err).Msg("failed to persist download event")
+		} else {
+			seq = event.Seq
+		}
+	}
+
+	w.EventBus.Publish(topic, &eventbus.Event{
+		Seq:           seq,
+		WorkflowRunID: args.WorkflowRunID,
+		AlbumID:       args.AlbumID,
+		Quality:       args.Quality,
+		EventType:     eventType,
+		Step:          step,
+		Message:       message,
+	})
+}
+
+func formatSpeed(bytesPerSec int64) string {
+	switch {
+	case bytesPerSec >= 1<<20:
+		return fmt.Sprintf("%.1f MB/s", float64(bytesPerSec)/float64(1<<20))
+	case bytesPerSec >= 1<<10:
+		return fmt.Sprintf("%.0f KB/s", float64(bytesPerSec)/float64(1<<10))
+	default:
+		return fmt.Sprintf("%d B/s", bytesPerSec)
+	}
+}