diff --git a/cmd/server/main.go b/cmd/server/main.go
index 7eb991f6..30ba500b 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -130,8 +130,7 @@ func main() {
 	maintenanceCancel := annotationService.StartDailyMaintenance()
 	defer maintenanceCancel()
 
-	queueProcessor := sync.NewSyncQueueProcessorWithConfig(queries, registry.SyncQueueConfig().Interval, registry.SyncQueueConfig().BatchSize)
-	queueProcessor.SetProgressService(progressService)
+	queueProcessor := sync.NewSyncQueueProcessorWithConfig(queries, progressService, registry.SyncQueueConfig().Interval, registry.SyncQueueConfig().BatchSize)
 	queueProcessor.SetAnnotationService(annotationService)
 
 	// Create library service
@@ -148,8 +147,7 @@ func main() {
 	worker := services.NewWorkerWithConfig(workerCfg.Size, workerCfg.QueueCap, connManager)
 	services.WorkerInstance = worker
 
-	koreaderHandler := handlers.NewKOReaderHandler(queries, connManager, queueProcessor)
-	koreaderHandler.SetProgressService(progressService)
+	koreaderHandler := handlers.NewKOReaderHandler(queries, connManager, queueProcessor, progressService)
 	koreaderHandler.SetAnnotationService(annotationService)
 	koreaderHandler.SetLibraryService(libraryService)
 	wsHandler := handlers.NewWSHandler(queries, connManager, cfg.JWTSecret, deviceAuthMiddleware)
@@ -169,8 +167,7 @@ func main() {
 	dashboardHandler := handlers.NewDashboardHandler(queries)
 	seriesHandler := handlers.NewSeriesHandler(queries)
 	filtersHandler := handlers.NewFiltersHandler(queries)
-	mediaHandler := handlers.NewMediaHandler(queries, libraryService, worker)
-	mediaHandler.SetProgressService(progressService)
+	mediaHandler := handlers.NewMediaHandler(queries, libraryService, progressService)
 	mediaHandler.SetAnnotationService(annotationService)
 	matchingHandler := handlers.NewMatchingHandler(queries, connManager)
 	jobsHandler := handlers.NewJobsHandler(queries, worker)
diff --git a/cmd/server/tests/test_helpers_test.go b/cmd/server/tests/test_helpers_test.go
index 9863fe83..c10de780 100644
--- a/cmd/server/tests/test_helpers_test.go
+++ b/cmd/server/tests/test_helpers_test.go
@@ -483,13 +483,11 @@ func setupTestServer(t *testing.T) *TestServerSetup {
 	progressService := wsync.NewProgressService(queries, connManager)
 	annotationService := wsync.NewAnnotationService(queries, connManager)
 
-	queueProcessor := wsync.NewSyncQueueProcessor(queries)
-	queueProcessor.SetProgressService(progressService)
+	queueProcessor := wsync.NewSyncQueueProcessor(queries, progressService)
 	queueCtx, queueCancel := context.WithCancel(context.Background())
 	go queueProcessor.Start(queueCtx)
 
-	koreaderHandler := handlers.NewKOReaderHandler(queries, connManager, queueProcessor)
-	koreaderHandler.SetProgressService(progressService)
+	koreaderHandler := handlers.NewKOReaderHandler(queries, connManager, queueProcessor, progressService)
 	koreaderHandler.SetAnnotationService(annotationService)
 	wsHandler := handlers.NewWSHandler(queries, connManager, cfg.JWTSecret, deviceAuthMiddleware)
 	conflictHandler := handlers.NewConflictHandler(queries, connManager)
@@ -510,8 +508,7 @@ func setupTestServer(t *testing.T) *TestServerSetup {
 	statisticsService := services.NewStatisticsService(queries)
 	statsHandler := handlers.NewStatsHandler(statisticsService)
 	seriesHandler := handlers.NewSeriesHandler(queries)
-	mediaHandler := handlers.NewMediaHandler(queries, libraryService, worker)
-	mediaHandler.SetProgressService(progressService)
+	mediaHandler := handlers.NewMediaHandler(queries, libraryService, progressService, worker)
 	mediaHandler.SetAnnotationService(annotationService)
 	matchingHandler := handlers.NewMatchingHandler(queries, connManager)
 
diff --git a/internal/handlers/kobo.go b/internal/handlers/kobo.go
index 155e11f3..3ddb4477 100644
--- a/internal/handlers/kobo.go
+++ b/internal/handlers/kobo.go
@@ -26,12 +26,8 @@ type KoboHandler struct {
 	bookResolver   *services.BookResolver
 }
 
-func NewKoboHandler(db *database.Queries, connManager *wsync.ConnectionManager) *KoboHandler {
-	return &KoboHandler{db: db, connManager: connManager, bookResolver: services.NewBookResolver(db)}
-}
-
-func (h *KoboHandler) SetProgressService(svc *wsync.ProgressService) {
-	h.progressSvc = svc
+func NewKoboHandler(db *database.Queries, connManager *wsync.ConnectionManager, progressSvc *wsync.ProgressService) *KoboHandler {
+	return &KoboHandler{db: db, connManager: connManager, progressSvc: progressSvc, bookResolver: services.NewBookResolver(db)}
 }
 
 func (h *KoboHandler) SetAnnotationService(svc *wsync.AnnotationService) {
@@ -446,29 +442,19 @@ func (h *KoboHandler) Markup(c *echo.Context) error {
 			}
 		}
 
-		if h.progressSvc != nil {
-			_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
-				MediaItemID:  pgMediaUUID,
-				UserID:       pgUserID,
-				Source:       "kobo",
-				DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
-				Percentage:   &percentage,
-				CurrentPage:  currentPage,
-				TotalPages:   totalPages,
-				DeviceType:   "kobo",
-				DeviceName:   device.DeviceName,
-				Broadcast:    true,
-				ClearLocator: true,
-			})
-		} else {
-			_, err = h.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-				MediaItemID:    pgMediaUUID,
-				UserID:         pgUserID,
-				Percentage:     pgtype.Float8{Float64: percentage, Valid: true},
-				LastSyncDevice: pgtype.Text{String: "kobo", Valid: true},
-				LastSyncSource: pgtype.Text{String: "kobo", Valid: true},
-			})
-		}
+		_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
+			MediaItemID:  pgMediaUUID,
+			UserID:       pgUserID,
+			Source:       "kobo",
+			DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
+			Percentage:   &percentage,
+			CurrentPage:  currentPage,
+			TotalPages:   totalPages,
+			DeviceType:   "kobo",
+			DeviceName:   device.DeviceName,
+			Broadcast:    true,
+			ClearLocator: true,
+		})
 
 		if err == nil {
 			markupsSynced++
@@ -580,31 +566,19 @@ func (h *KoboHandler) Markup(c *echo.Context) error {
 					epubcfi = *convertedCFI
 				}
 
-				if h.progressSvc != nil {
-					_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
-						MediaItemID:     pgMediaUUID,
-						UserID:          pgUserID,
-						Source:          "kobo",
-						DeviceID:        pgtype.UUID{Bytes: deviceID, Valid: true},
-						Epubcfi:         &epubcfi,
-						ContextText:     contextText,
-						Chapter:         &chapter,
-						ChapterProgress: &chapterProgress,
-						DeviceType:      "kobo",
-						DeviceName:      device.DeviceName,
-						Broadcast:       false,
-					})
-				} else {
-					_, err = h.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-						MediaItemID:     pgMediaUUID,
-						UserID:          pgUserID,
-						Epubcfi:         pgtype.Text{String: epubcfi, Valid: epubcfi != ""},
-						Chapter:         pgtype.Int4{Int32: int32(bookmarkSync.Chapter), Valid: true},
-						ChapterProgress: pgtype.Float8{Float64: 0.5, Valid: true},
-						LastSyncDevice:  pgtype.Text{String: "kobo", Valid: true},
-						LastSyncSource:  pgtype.Text{String: "kobo", Valid: true},
-					})
-				}
+				_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
+					MediaItemID:     pgMediaUUID,
+					UserID:          pgUserID,
+					Source:          "kobo",
+					DeviceID:        pgtype.UUID{Bytes: deviceID, Valid: true},
+					Epubcfi:         &epubcfi,
+					ContextText:     contextText,
+					Chapter:         &chapter,
+					ChapterProgress: &chapterProgress,
+					DeviceType:      "kobo",
+					DeviceName:      device.DeviceName,
+					Broadcast:       false,
+				})
 				if err != nil {
 					fmt.Printf("Failed to store last-read-place: %v", err)
 				}
@@ -797,27 +771,17 @@ func (h *KoboHandler) AnalyticsGettests(c *echo.Context) error {
 		pgMediaUUID := pgtype.UUID{Bytes: bookhoardUUID, Valid: true}
 		percentage := test.PercentRead / 100.0
 
-		if h.progressSvc != nil {
-			_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
-				MediaItemID:  pgMediaUUID,
-				UserID:       pgUserID,
-				Source:       "kobo",
-				DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
-				Percentage:   &percentage,
-				DeviceType:   "kobo",
-				DeviceName:   device.DeviceName,
-				Broadcast:    true,
-				ClearLocator: true,
-			})
-		} else {
-			_, err = h.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-				MediaItemID:    pgMediaUUID,
-				UserID:         pgUserID,
-				Percentage:     pgtype.Float8{Float64: percentage, Valid: true},
-				LastSyncDevice: pgtype.Text{String: "kobo", Valid: true},
-				LastSyncSource: pgtype.Text{String: "kobo", Valid: true},
-			})
-		}
+		_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
+			MediaItemID:  pgMediaUUID,
+			UserID:       pgUserID,
+			Source:       "kobo",
+			DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
+			Percentage:   &percentage,
+			DeviceType:   "kobo",
+			DeviceName:   device.DeviceName,
+			Broadcast:    true,
+			ClearLocator: true,
+		})
 	}
 
 	_, err := h.db.UpdateDeviceLastSync(c.Request().Context(), device.ID)
@@ -860,27 +824,17 @@ func (h *KoboHandler) SyncFromServer(c *echo.Context) error {
 		pgMediaUUID := pgtype.UUID{Bytes: bookhoardUUID, Valid: true}
 		percentage := syncData.PercentRead / 100.0
 
-		if h.progressSvc != nil {
-			_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
-				MediaItemID:  pgMediaUUID,
-				UserID:       pgUserID,
-				Source:       "bookhoard",
-				DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
-				Percentage:   &percentage,
-				DeviceType:   "kobo",
-				DeviceName:   device.DeviceName,
-				Broadcast:    false,
-				ClearLocator: true,
-			})
-		} else {
-			_, err = h.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-				MediaItemID:    pgMediaUUID,
-				UserID:         pgUserID,
-				Percentage:     pgtype.Float8{Float64: percentage, Valid: true},
-				LastSyncDevice: pgtype.Text{String: "kobo", Valid: true},
-				LastSyncSource: pgtype.Text{String: "bookhoard", Valid: true},
-			})
-		}
+		_, err = h.progressSvc.SaveProgress(c.Request().Context(), wsync.SaveProgressRequest{
+			MediaItemID:  pgMediaUUID,
+			UserID:       pgUserID,
+			Source:       "bookhoard",
+			DeviceID:     pgtype.UUID{Bytes: deviceID, Valid: true},
+			Percentage:   &percentage,
+			DeviceType:   "kobo",
+			DeviceName:   device.DeviceName,
+			Broadcast:    false,
+			ClearLocator: true,
+		})
 
 		if err == nil {
 			booksSynced++
diff --git a/internal/handlers/koreader.go b/internal/handlers/koreader.go
index f2d63626..4532ed2d 100644
--- a/internal/handlers/koreader.go
+++ b/internal/handlers/koreader.go
@@ -36,19 +36,16 @@ type LibraryPathResolver interface {
 	ResolveMediaPath(ctx context.Context, libraryID pgtype.UUID, relativePath string) (string, error)
 }
 
-func NewKOReaderHandler(db *database.Queries, connManager *wsync.ConnectionManager, queue *wsync.SyncQueueProcessor) *KOReaderHandler {
+func NewKOReaderHandler(db *database.Queries, connManager *wsync.ConnectionManager, queue *wsync.SyncQueueProcessor, progressSvc *wsync.ProgressService) *KOReaderHandler {
 	return &KOReaderHandler{
 		db:           db,
 		connManager:  connManager,
 		queue:        queue,
+		progressSvc:  progressSvc,
 		bookResolver: services.NewBookResolver(db),
 	}
 }
 
-func (h *KOReaderHandler) SetProgressService(svc *wsync.ProgressService) {
-	h.progressSvc = svc
-}
-
 func (h *KOReaderHandler) SetAnnotationService(svc *wsync.AnnotationService) {
 	h.annotationSvc = svc
 }
@@ -878,138 +875,77 @@ func (h *KOReaderHandler) updateProgressForBook(c *echo.Context, deviceID pgtype
 		deviceModel = "KOReader Device"
 	}
 
-	if h.progressSvc != nil {
-		epubcfi := book.Epubcfi
-		// No position pointer from the device, or a conversion that
-		// declined below: the write is percentage-only by intent. The
-		// service then clears any inherited stale anchor instead of
-		// re-pairing it with the new percentage.
-		clearLocator := epubcfi == nil
-		if epubcfi != nil && wsync.IsCREXPointer(*epubcfi) {
-			// Same facade every annotation uses: cached converter,
-			// structural-first resolution, guarded fallbacks. The facade
-			// passes non-reflowable formats through untouched.
-			ec := h.loadAnnotationEpub(ctx, mediaItemID)
-			if ec.convertible() {
-				pct := 0.0
-				if book.Percentage >= 0 {
-					pct = book.Percentage
-				}
-				contextText := ""
-				if book.ContextText != nil {
-					contextText = *book.ContextText
-				}
-				loc := wsync.ConvertToCanonical(wsync.LocatorSourceKOReader, *epubcfi, pct, contextText, ec.mediaItem.FormatGroup, ec.epubPath, "")
-				switch {
-				case strings.HasPrefix(loc.CFI, "epubcfi(") &&
-					(loc.Precision == "structural" || loc.Precision == "exact"):
-					converted := loc.CFI
-					epubcfi = &converted
-					log.Printf("Bookhoard: CRE→CFI converted progress (%s) to %s", loc.Precision, converted)
-				case loc.CFI != "" && loc.CFI != *epubcfi &&
-					(loc.Precision == "element" || loc.Precision == "section"):
-					// Fragment-ID positions resolve to a section href: keep
-					// serving it (legacy behavior).
-					converted := loc.CFI
-					epubcfi = &converted
-					log.Printf("Bookhoard: CRE→CFI converted progress (%s) to href %s", loc.Precision, converted)
-				default:
-					// Low-confidence (percentage/fallback): store no
-					// canonical locator — the row's percentage restores
-					// approximately instead of a confidently-wrong CFI,
-					// and the device keeps its own native position.
-					log.Printf("Bookhoard: CRE→CFI conversion low-confidence (%s) for %s; storing percentage only", loc.Precision, *epubcfi)
-					epubcfi = nil
-					clearLocator = true
-				}
+	epubcfi := book.Epubcfi
+	// No position pointer from the device, or a conversion that
+	// declined below: the write is percentage-only by intent. The
+	// service then clears any inherited stale anchor instead of
+	// re-pairing it with the new percentage.
+	clearLocator := epubcfi == nil
+	if epubcfi != nil && wsync.IsCREXPointer(*epubcfi) {
+		// Same facade every annotation uses: cached converter,
+		// structural-first resolution, guarded fallbacks. The facade
+		// passes non-reflowable formats through untouched.
+		ec := h.loadAnnotationEpub(ctx, mediaItemID)
+		if ec.convertible() {
+			pct := 0.0
+			if book.Percentage >= 0 {
+				pct = book.Percentage
+			}
+			contextText := ""
+			if book.ContextText != nil {
+				contextText = *book.ContextText
+			}
+			loc := wsync.ConvertToCanonical(wsync.LocatorSourceKOReader, *epubcfi, pct, contextText, ec.mediaItem.FormatGroup, ec.epubPath, "")
+			switch {
+			case strings.HasPrefix(loc.CFI, "epubcfi(") &&
+				(loc.Precision == "structural" || loc.Precision == "exact"):
+				converted := loc.CFI
+				epubcfi = &converted
+				log.Printf("Bookhoard: CRE→CFI converted progress (%s) to %s", loc.Precision, converted)
+			case loc.CFI != "" && loc.CFI != *epubcfi &&
+				(loc.Precision == "element" || loc.Precision == "section"):
+				// Fragment-ID positions resolve to a section href: keep
+				// serving it (legacy behavior).
+				converted := loc.CFI
+				epubcfi = &converted
+				log.Printf("Bookhoard: CRE→CFI converted progress (%s) to href %s", loc.Precision, converted)
+			default:
+				// Low-confidence (percentage/fallback): store no
+				// canonical locator — the row's percentage restores
+				// approximately instead of a confidently-wrong CFI,
+				// and the device keeps its own native position.
+				log.Printf("Bookhoard: CRE→CFI conversion low-confidence (%s) for %s; storing percentage only", loc.Precision, *epubcfi)
+				epubcfi = nil
+				clearLocator = true
 			}
 		}
-
-		saveReq := wsync.SaveProgressRequest{
-			MediaItemID:     mediaItemID,
-			UserID:          userID,
-			Source:          "koreader",
-			DeviceID:        deviceID,
-			Percentage:      &book.Percentage,
-			Epubcfi:         epubcfi,
-			ContextText:     book.ContextText,
-			Chapter:         book.Chapter,
-			CharacterOffset: book.Character,
-			CurrentPage:     book.Page,
-			TotalPages:      book.TotalPages,
-			DeviceType:      "koreader",
-			DeviceName:      deviceModel,
-			Broadcast:       true,
-			ClearLocator:    clearLocator,
-		}
-
-		_, err := h.progressSvc.SaveProgress(ctx, saveReq)
-		if err != nil {
-			return err
-		}
-		h.processBookAnnotations(ctx, deviceID, userID, mediaItemID, book)
-		return nil
 	}
 
-	_, err := h.db.UpdateUniversalProgress(ctx, database.UpdateUniversalProgressParams{
+	saveReq := wsync.SaveProgressRequest{
 		MediaItemID:     mediaItemID,
 		UserID:          userID,
-		Percentage:      pgtype.Float8{Float64: book.Percentage, Valid: true},
-		Epubcfi:         textPtrToPgText(book.Epubcfi),
-		Chapter:         intPtrToPgInt4(book.Chapter),
-		ChapterProgress: pgtype.Float8{Float64: book.Percentage, Valid: true},
-		CharacterOffset: int64PtrToPgInt8(book.Character),
-		CurrentPage:     intPtrToPgInt4(book.Page),
-		TotalPages:      intPtrToPgInt4(book.TotalPages),
-		LastSyncDevice:  pgtype.Text{String: "koreader", Valid: true},
-		LastSyncSource:  pgtype.Text{String: "koreader", Valid: true},
-		ViewportY:       pgtype.Float8{},
-		ScrollPositionX: pgtype.Float8{},
-		ScrollPositionY: pgtype.Float8{},
-		PanelNumber:     pgtype.Int4{},
-		ReadingMode:     pgtype.Text{},
-		ZoomLevel:       pgtype.Float8{},
-	})
-	if err != nil {
+		Source:          "koreader",
+		DeviceID:        deviceID,
+		Percentage:      &book.Percentage,
+		Epubcfi:         epubcfi,
+		ContextText:     book.ContextText,
+		Chapter:         book.Chapter,
+		CharacterOffset: book.Character,
+		CurrentPage:     book.Page,
+		TotalPages:      book.TotalPages,
+		DeviceType:      "koreader",
+		DeviceName:      deviceModel,
+		Broadcast:       true,
+		ClearLocator:    clearLocator,
+	}
+
+	if _, err := h.progressSvc.SaveProgress(ctx, saveReq); err != nil {
 		return err
 	}
-
-	h.connManager.BroadcastProgressUpdate(
-		mediaItemID.Bytes,
-		book.Percentage,
-		wsync.SourceDevice{
-			ID:   uuid.UUID(deviceID.Bytes).String(),
-			Name: deviceModel,
-			Type: "koreader",
-		},
-	)
-
 	h.processBookAnnotations(ctx, deviceID, userID, mediaItemID, book)
-
 	return nil
 }
 
-func textPtrToPgText(s *string) pgtype.Text {
-	if s != nil {
-		return pgtype.Text{String: *s, Valid: true}
-	}
-	return pgtype.Text{}
-}
-
-func intPtrToPgInt4(i *int) pgtype.Int4 {
-	if i != nil {
-		return pgtype.Int4{Int32: int32(*i), Valid: true}
-	}
-	return pgtype.Int4{}
-}
-
-func int64PtrToPgInt8(i *int64) pgtype.Int8 {
-	if i != nil {
-		return pgtype.Int8{Int64: *i, Valid: true}
-	}
-	return pgtype.Int8{}
-}
-
 type KOReaderResolveResponse struct {
 	BookUUID string `json:"book_uuid"`
 	SHA256   string `json:"sha256,omitempty"`
diff --git a/internal/handlers/media.go b/internal/handlers/media.go
index 1c53149b..451e14ff 100644
--- a/internal/handlers/media.go
+++ b/internal/handlers/media.go
@@ -180,11 +180,15 @@ type MediaHandler struct {
 	annotationSvc  *wsync.AnnotationService
 }
 
-func NewMediaHandler(db *database.Queries, libraryService *services.LibraryService, worker ...*services.Worker) *MediaHandler {
+// NewMediaHandler requires the shared ProgressService — progress writes
+// must funnel through SaveProgress (the LWW-seeded canonical writer);
+// a nil service has nowhere to fall back to and must not be wired.
+func NewMediaHandler(db *database.Queries, libraryService *services.LibraryService, progressSvc *wsync.ProgressService, worker ...*services.Worker) *MediaHandler {
 	mh := &MediaHandler{
 		db:             db,
 		libraryService: libraryService,
 		searchService:  services.NewSearchService(db),
+		progressSvc:    progressSvc,
 	}
 	if len(worker) > 0 && worker[0] != nil {
 		mh.worker = worker[0]
@@ -192,10 +196,6 @@ func NewMediaHandler(db *database.Queries, libraryService *services.LibraryServi
 	return mh
 }
 
-func (mh *MediaHandler) SetProgressService(svc *wsync.ProgressService) {
-	mh.progressSvc = svc
-}
-
 func (mh *MediaHandler) SetAnnotationService(svc *wsync.AnnotationService) {
 	mh.annotationSvc = svc
 }
@@ -1281,66 +1281,21 @@ func (mh *MediaHandler) UpdateMediaReadingProgress(c *echo.Context) error {
 	req.DeviceName = deviceLabel
 	req.Broadcast = true
 
-	if mh.progressSvc != nil {
-		if req.Percentage != nil && *req.Percentage < 0.005 {
-			existing, err := mh.db.GetUniversalProgress(c.Request().Context(), database.GetUniversalProgressParams{
-				MediaItemID: pgtype.UUID{Bytes: mediaUUID, Valid: true},
-				UserID:      pgtype.UUID{Bytes: userUUID, Valid: true},
-			})
-			if err == nil && existing.Percentage.Valid && existing.Percentage.Float64 > 0.01 {
-				return c.JSON(http.StatusOK, map[string]string{"status": "ignored"})
-			}
+	if req.Percentage != nil && *req.Percentage < 0.005 {
+		existing, err := mh.db.GetUniversalProgress(c.Request().Context(), database.GetUniversalProgressParams{
+			MediaItemID: pgtype.UUID{Bytes: mediaUUID, Valid: true},
+			UserID:      pgtype.UUID{Bytes: userUUID, Valid: true},
+		})
+		if err == nil && existing.Percentage.Valid && existing.Percentage.Float64 > 0.01 {
+			return c.JSON(http.StatusOK, map[string]string{"status": "ignored"})
 		}
-
-		result, err := mh.progressSvc.SaveProgress(c.Request().Context(), req)
-		if err != nil {
-			return c.JSON(http.StatusInternalServerError, map[string]string{"error": err.Error()})
-		}
-		return c.JSON(http.StatusOK, result)
 	}
 
-	percentage := 0.0
-	if req.Percentage != nil {
-		percentage = *req.Percentage
-	}
-	epubcfi := ""
-	if req.Epubcfi != nil {
-		epubcfi = *req.Epubcfi
-	}
-	currentPage := int32(0)
-	if req.CurrentPage != nil {
-		currentPage = int32(*req.CurrentPage)
-	}
-	totalPages := int32(0)
-	if req.TotalPages != nil {
-		totalPages = int32(*req.TotalPages)
-	}
-
-	progress, err := mh.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-		MediaItemID:     pgtype.UUID{Bytes: mediaUUID, Valid: true},
-		UserID:          pgtype.UUID{Bytes: userUUID, Valid: true},
-		Percentage:      pgtype.Float8{Float64: percentage, Valid: true},
-		CharacterOffset: pgtype.Int8{Valid: false},
-		Epubcfi:         pgtype.Text{String: epubcfi, Valid: epubcfi != ""},
-		Chapter:         pgtype.Int4{Valid: false},
-		ChapterProgress: pgtype.Float8{Valid: false},
-		ViewportX:       pgtype.Float8{Valid: false},
-		ViewportY:       pgtype.Float8{Valid: false},
-		ZoomLevel:       pgtype.Float8{Valid: false},
-		ScrollPositionX: pgtype.Float8{Valid: false},
-		ScrollPositionY: pgtype.Float8{Valid: false},
-		PanelNumber:     pgtype.Int4{Valid: false},
-		ReadingMode:     pgtype.Text{Valid: false},
-		LastSyncDevice:  pgtype.Text{String: "web", Valid: true},
-		LastSyncSource:  pgtype.Text{String: "web", Valid: true},
-		CurrentPage:     pgtype.Int4{Int32: currentPage, Valid: true},
-		TotalPages:      pgtype.Int4{Int32: totalPages, Valid: totalPages > 0},
-	})
+	result, err := mh.progressSvc.SaveProgress(c.Request().Context(), req)
 	if err != nil {
 		return c.JSON(http.StatusInternalServerError, map[string]string{"error": err.Error()})
 	}
-
-	return c.JSON(http.StatusOK, progress)
+	return c.JSON(http.StatusOK, result)
 }
 
 // DeleteMediaReadingProgress handles DELETE /api/media-items/:id/progress
diff --git a/internal/handlers/progress_test.go b/internal/handlers/progress_test.go
index fa754a00..453494a0 100644
--- a/internal/handlers/progress_test.go
+++ b/internal/handlers/progress_test.go
@@ -30,51 +30,6 @@ func TestGetDeviceIcon_Unknown(t *testing.T) {
 	assert.Equal(t, "📚", result)
 }
 
-func TestTextPtrToPgText(t *testing.T) {
-	t.Run("nil returns invalid", func(t *testing.T) {
-		result := textPtrToPgText(nil)
-		assert.False(t, result.Valid)
-	})
-	t.Run("non-nil returns valid", func(t *testing.T) {
-		s := "epubcfi(/6/4/2:10)"
-		result := textPtrToPgText(&s)
-		assert.True(t, result.Valid)
-		assert.Equal(t, s, result.String)
-	})
-	t.Run("empty string returns valid", func(t *testing.T) {
-		s := ""
-		result := textPtrToPgText(&s)
-		assert.True(t, result.Valid)
-		assert.Equal(t, "", result.String)
-	})
-}
-
-func TestIntPtrToPgInt4(t *testing.T) {
-	t.Run("nil returns invalid", func(t *testing.T) {
-		result := intPtrToPgInt4(nil)
-		assert.False(t, result.Valid)
-	})
-	t.Run("non-nil returns valid", func(t *testing.T) {
-		v := 5
-		result := intPtrToPgInt4(&v)
-		assert.True(t, result.Valid)
-		assert.Equal(t, int32(5), result.Int32)
-	})
-}
-
-func TestInt64PtrToPgInt8(t *testing.T) {
-	t.Run("nil returns invalid", func(t *testing.T) {
-		result := int64PtrToPgInt8(nil)
-		assert.False(t, result.Valid)
-	})
-	t.Run("non-nil returns valid", func(t *testing.T) {
-		v := int64(10000)
-		result := int64PtrToPgInt8(&v)
-		assert.True(t, result.Valid)
-		assert.Equal(t, int64(10000), result.Int64)
-	})
-}
-
 func TestFloat64PtrHelpers(t *testing.T) {
 	t.Run("pgtype float64 valid", func(t *testing.T) {
 		v := pgtype.Float8{Float64: 0.5, Valid: true}
diff --git a/internal/router/sync.go b/internal/router/sync.go
index cf62c2e9..bafe94bc 100644
--- a/internal/router/sync.go
+++ b/internal/router/sync.go
@@ -37,8 +37,7 @@ func registerSyncRoutes(cfg *Config) {
 	// Kobo sync routes (device authentication required)
 	// Kobo devices use URL path: /api/sync/kobo/{token}/markup
 	// API clients can use Authorization header: Authorization: Bearer {token}
-	koboHandler := handlers.NewKoboHandler(cfg.Queries, cfg.ConnManager)
-	koboHandler.SetProgressService(cfg.ProgressService)
+	koboHandler := handlers.NewKoboHandler(cfg.Queries, cfg.ConnManager, cfg.ProgressService)
 	koboHandler.SetAnnotationService(cfg.AnnotationService)
 	koboHandler.SetLibraryService(cfg.LibraryService)
 	koboSync := e.Group("/api/sync/kobo/:token")
diff --git a/internal/sync/queue.go b/internal/sync/queue.go
index 6f7bf152..a0601018 100644
--- a/internal/sync/queue.go
+++ b/internal/sync/queue.go
@@ -73,26 +73,26 @@ type SyncQueueItem struct {
 	ProcessedAt  *time.Time
 }
 
-func NewSyncQueueProcessor(db *database.Queries) *SyncQueueProcessor {
-	return NewSyncQueueProcessorWithConfig(db, 5*time.Second, 50)
+// NewSyncQueueProcessor requires the shared ProgressService — queue
+// progress entries flush through SaveProgress (the LWW-seeded canonical
+// writer); a nil service has nowhere to fall back to and must not be wired.
+func NewSyncQueueProcessor(db *database.Queries, progressSvc *ProgressService) *SyncQueueProcessor {
+	return NewSyncQueueProcessorWithConfig(db, progressSvc, 5*time.Second, 50)
 }
 
 // NewSyncQueueProcessorWithConfig constructs a processor with the given flush
 // interval and batch size. Used at startup to source values from the settings
 // registry.
-func NewSyncQueueProcessorWithConfig(db *database.Queries, interval time.Duration, batchSize int) *SyncQueueProcessor {
+func NewSyncQueueProcessorWithConfig(db *database.Queries, progressSvc *ProgressService, interval time.Duration, batchSize int) *SyncQueueProcessor {
 	return &SyncQueueProcessor{
 		db:           db,
+		progressSvc:  progressSvc,
 		progressChan: make(chan *ProgressUpdate, 100),
 		interval:     interval,
 		batchSize:    batchSize,
 	}
 }
 
-func (p *SyncQueueProcessor) SetProgressService(svc *ProgressService) {
-	p.progressSvc = svc
-}
-
 func (p *SyncQueueProcessor) SetAnnotationService(svc *AnnotationService) {
 	p.annotationSvc = svc
 }
@@ -432,89 +432,40 @@ func (p *SyncQueueProcessor) syncProgress(ctx context.Context, userID pgtype.UUI
 		source = v
 	}
 
-	if p.progressSvc != nil {
-		req := SaveProgressRequest{
-			MediaItemID: mediaItemID,
-			UserID:      userID,
-			Source:      source,
-			Percentage:  &percentage,
-			Broadcast:   false,
-		}
-		if v, ok := syncData["epubcfi"].(string); ok {
-			req.Epubcfi = &v
-		}
-		// Entries without a CFI are percentage-only by intent: declare it
-		// so the service clears any inherited stale anchor instead of
-		// re-pairing it with this percentage.
-		req.ClearLocator = req.Epubcfi == nil
-		if v, ok := syncData["context_text"].(string); ok {
-			req.ContextText = &v
-		}
-		if v, ok := syncData["chapter"].(float64); ok {
-			ch := int(v)
-			req.Chapter = &ch
-		}
-		if v, ok := syncData["character"].(float64); ok {
-			co := int64(v)
-			req.CharacterOffset = &co
-		}
-		if v, ok := syncData["page"].(float64); ok {
-			pg := int(v)
-			req.CurrentPage = &pg
-		}
-		if v, ok := syncData["total_pages"].(float64); ok {
-			tp := int(v)
-			req.TotalPages = &tp
-		}
-		_, err := p.progressSvc.SaveProgress(ctx, req)
-		return err
+	req := SaveProgressRequest{
+		MediaItemID: mediaItemID,
+		UserID:      userID,
+		Source:      source,
+		Percentage:  &percentage,
+		Broadcast:   false,
 	}
-
-	var epubcfi pgtype.Text
 	if v, ok := syncData["epubcfi"].(string); ok {
-		epubcfi = pgtype.Text{String: v, Valid: true}
+		req.Epubcfi = &v
+	}
+	// Entries without a CFI are percentage-only by intent: declare it
+	// so the service clears any inherited stale anchor instead of
+	// re-pairing it with this percentage.
+	req.ClearLocator = req.Epubcfi == nil
+	if v, ok := syncData["context_text"].(string); ok {
+		req.ContextText = &v
 	}
-
-	var chapter pgtype.Int4
 	if v, ok := syncData["chapter"].(float64); ok {
-		chapter = pgtype.Int4{Int32: int32(v), Valid: true}
+		ch := int(v)
+		req.Chapter = &ch
 	}
-
-	var characterOffset pgtype.Int8
 	if v, ok := syncData["character"].(float64); ok {
-		characterOffset = pgtype.Int8{Int64: int64(v), Valid: true}
+		co := int64(v)
+		req.CharacterOffset = &co
 	}
-
-	var currentPage pgtype.Int4
 	if v, ok := syncData["page"].(float64); ok {
-		currentPage = pgtype.Int4{Int32: int32(v), Valid: true}
+		pg := int(v)
+		req.CurrentPage = &pg
 	}
-
-	var totalPages pgtype.Int4
 	if v, ok := syncData["total_pages"].(float64); ok {
-		totalPages = pgtype.Int4{Int32: int32(v), Valid: true}
+		tp := int(v)
+		req.TotalPages = &tp
 	}
-
-	_, err := p.db.UpdateUniversalProgress(ctx, database.UpdateUniversalProgressParams{
-		MediaItemID:     mediaItemID,
-		UserID:          userID,
-		Percentage:      pgtype.Float8{Float64: percentage, Valid: true},
-		Epubcfi:         epubcfi,
-		Chapter:         chapter,
-		ChapterProgress: pgtype.Float8{Float64: percentage, Valid: true},
-		CharacterOffset: characterOffset,
-		CurrentPage:     currentPage,
-		TotalPages:      totalPages,
-		LastSyncDevice:  pgtype.Text{String: source, Valid: true},
-		LastSyncSource:  pgtype.Text{String: source, Valid: true},
-		ViewportX:       pgtype.Float8{},
-		ScrollPositionX: pgtype.Float8{},
-		ScrollPositionY: pgtype.Float8{},
-		PanelNumber:     pgtype.Int4{},
-		ReadingMode:     pgtype.Text{},
-		ZoomLevel:       pgtype.Float8{},
-	})
-
+	_, err := p.progressSvc.SaveProgress(ctx, req)
 	return err
 }
 
diff --git a/internal/sync/queue_test.go b/internal/sync/queue_test.go
index f916e0e0..669f936f 100644
--- a/internal/sync/queue_test.go
+++ b/internal/sync/queue_test.go
@@ -8,7 +8,7 @@ import (
 )
 
 func TestCalculateNextRetry(t *testing.T) {
-	processor := NewSyncQueueProcessor(nil)
+	processor := NewSyncQueueProcessor(nil, nil)
 
 	tests := []struct {
 		name     string