feat(ui): add scan progress and error reporting to UI (#4094)

* feat(scanner): add LastScanError tracking to scanner status

- Introduced LastScanErrorKey constant for error tracking.
- Updated StatusInfo struct to include LastError field.
- Modified scanner logic to store and retrieve last scan error.
- Enhanced ScanStatus response to include error information.
- Updated UI components to display last scan error when applicable.
- Added tests to verify last scan error functionality.

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

* feat(scanner): enhance scan status with type and elapsed time tracking

- Added LastScanTypeKey and LastScanStartTimeKey constants for tracking scan type and start time.
- Updated StatusInfo struct to include ScanType and ElapsedTime fields.
- Implemented getScanInfo method to retrieve scan type, elapsed time, and last error.
- Modified scanner logic to store scan type and start time during scans.
- Enhanced ScanStatus response and UI components to display scan type and elapsed time.
- Added formatShortDuration utility for better elapsed time representation.
- Updated activity reducer to handle new scan status fields.

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

* refactor(tests): consolidate controller status tests into a single file

- Removed the old controller_status_test.go file.
- Merged relevant tests into the new controller_test.go file for better organization and maintainability.
- Ensured all existing test cases for controller status are preserved and functional.

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

* Fix formatting issues

* refactor(scanner): update getScanInfo method documentation

---------

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

scanner/controller_test.go

@@ -0,0 +1,57 @@
+package scanner_test
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/core/artwork"
+	"github.com/navidrome/navidrome/core/metrics"
+	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/persistence"
+	"github.com/navidrome/navidrome/scanner"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Controller", func() {
+	var ctx context.Context
+	var ds *tests.MockDataStore
+	var ctrl scanner.Scanner
+
+	Describe("Status", func() {
+		BeforeEach(func() {
+			ctx = context.Background()
+			db.Init(ctx)
+			DeferCleanup(func() { Expect(tests.ClearDB()).To(Succeed()) })
+			DeferCleanup(configtest.SetupConfig())
+			ds = &tests.MockDataStore{RealDS: persistence.New(db.Db())}
+			ds.MockedProperty = &tests.MockedPropertyRepo{}
+			ctrl = scanner.New(ctx, ds, artwork.NoopCacheWarmer(), events.NoopBroker(), core.NewPlaylists(ds), metrics.NewNoopInstance())
+			Expect(ds.Library(ctx).Put(&model.Library{ID: 1, Name: "lib", Path: "/tmp"})).To(Succeed())
+		})
+
+		It("includes last scan error", func() {
+			Expect(ds.Property(ctx).Put(consts.LastScanErrorKey, "boom")).To(Succeed())
+			status, err := ctrl.Status(ctx)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(status.LastError).To(Equal("boom"))
+		})
+
+		It("includes scan type and error in status", func() {
+			// Set up test data in property repo
+			Expect(ds.Property(ctx).Put(consts.LastScanErrorKey, "test error")).To(Succeed())
+			Expect(ds.Property(ctx).Put(consts.LastScanTypeKey, "full")).To(Succeed())
+
+			// Get status and verify basic info
+			status, err := ctrl.Status(ctx)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(status.LastError).To(Equal("test error"))
+			Expect(status.ScanType).To(Equal("full"))
+		})
+	})
+})