fix(scanner): store scan errors in the database and update UI error handling

Signed-off-by: Deluan <deluan@navidrome.org>

scanner/controller.go

@@ -224,6 +224,10 @@ func (s *controller) ScanFolders(requestCtx context.Context, fullScan bool, targ
 	for _, w := range scanWarnings {
 		log.Warn(ctx, fmt.Sprintf("Scan warning: %s", w))
 	}
+	// Store scan error in database so it can be displayed in the UI
+	if scanError != nil {
+		_ = s.ds.Property(ctx).Put(consts.LastScanErrorKey, scanError.Error())
+	}
 	// If changes were detected, send a refresh event to all clients
 	if s.changesDetected {
 		log.Debug(ctx, "Library changes imported. Sending refresh event")

scanner/phase_1_folders.go

@@ -40,7 +40,7 @@ func createPhaseFolders(ctx context.Context, state *scanState, ds model.DataStor
 		job, err := newScanJob(ctx, ds, cw, lib, state.fullScan, targetFolders)
 		if err != nil {
 			log.Error(ctx, "Scanner: Error creating scan context", "lib", lib.Name, err)
-			state.sendWarning(err.Error())
+			state.sendError(err)
 			continue
 		}
 		jobs = append(jobs, job)

scanner/scanner_multilibrary_test.go

@@ -51,8 +51,14 @@ var _ = Describe("Scanner - Multi-Library", Ordered, func() {
 
 	BeforeEach(func() {
 		DeferCleanup(configtest.SetupConfig())
+		conf.Server.MusicFolder = "default:///music" // Use a distinct schema for the default library
 		conf.Server.DevExternalScanner = false
 
+		// Register an empty fake storage for the default library
+		emptyFS := storagetest.FakeFS{}
+		emptyFS.SetFiles(fstest.MapFS{})
+		storagetest.Register("default", &emptyFS)
+
 		db.Init(ctx)
 		DeferCleanup(func() {
 			Expect(tests.ClearDB()).To(Succeed())
@@ -770,7 +776,7 @@ var _ = Describe("Scanner - Multi-Library", Ordered, func() {
 				// Second scan should recover and import all rock content
 				warnings, err = s.ScanAll(ctx, true)
 				Expect(err).ToNot(HaveOccurred())
-				Expect(warnings).ToNot(BeEmpty(), "Should have warnings for temporary disk error")
+				Expect(warnings).To(BeEmpty(), "Should have no warnings after error recovery")
 
 				// Verify both libraries now have content (at least jazz should work)
 				rockFiles, err := ds.MediaFile(ctx).GetAll(model.QueryOptions{