refactor: remove dead code across Dart and Go layers

- drop unused widgets (AnimatedStateSwitcher, GridSkeleton,
  adjacentHorizontalPageRoute, buildRemovalAnimation, SwingIcon,
  BottomSheetOptionTile) and empty _buildInfoCard placeholders
- drop test-only Go wrapper methods (GetDownloadURL, MatchTrack,
  CheckAvailability 7-arg, CustomSearchForItemID) and their parsers
- drop unused httputil getters/validators and hand-rolled base64
  decoder in favor of encoding/base64
- remove unused riverpod_generator dev dependency

go_backend/audio_metadata.go

@@ -2,6 +2,7 @@ package gobackend
 
 import (
 	"bytes"
+	"encoding/base64"
 	"encoding/binary"
 	"fmt"
 	"io"
@@ -1460,13 +1461,20 @@ func extractPictureFromVorbisComments(data []byte) ([]byte, string) {
 
 		key := "METADATA_BLOCK_PICTURE="
 		if len(comment) > len(key) && strings.ToUpper(string(comment[:len(key)])) == key {
-			b64Data := comment[len(key):]
-			decoded := make([]byte, base64StdDecodeLen(len(b64Data)))
-			n, err := base64StdDecode(decoded, b64Data)
+			cleaned := strings.Map(func(r rune) rune {
+				switch r {
+				case '\n', '\r', ' ', '\t':
+					return -1
+				}
+				return r
+			}, string(comment[len(key):]))
+			decoded, err := base64.StdEncoding.DecodeString(cleaned)
+			if err != nil {
+				decoded, err = base64.RawStdEncoding.DecodeString(cleaned)
+			}
 			if err != nil {
 				continue
 			}
-			decoded = decoded[:n]
 
 			imageData, mimeType := parseFLACPictureBlock(decoded)
 			if len(imageData) > 0 {
@@ -1520,67 +1528,6 @@ func parseFLACPictureBlock(data []byte) ([]byte, string) {
 	return imageData, mimeType
 }
 
-func base64StdDecodeLen(n int) int {
-	return n * 6 / 8
-}
-
-func base64StdDecode(dst, src []byte) (int, error) {
-	const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
-
-	decodeMap := make([]byte, 256)
-	for i := range decodeMap {
-		decodeMap[i] = 0xFF
-	}
-	for i := 0; i < len(alphabet); i++ {
-		decodeMap[alphabet[i]] = byte(i)
-	}
-
-	si, di := 0, 0
-	for si < len(src) {
-		for si < len(src) && (src[si] == '\n' || src[si] == '\r' || src[si] == ' ' || src[si] == '\t') {
-			si++
-		}
-		if si >= len(src) {
-			break
-		}
-
-		var vals [4]byte
-		var valCount int
-		for valCount < 4 && si < len(src) {
-			c := src[si]
-			si++
-			if c == '=' {
-				vals[valCount] = 0
-				valCount++
-			} else if c == '\n' || c == '\r' || c == ' ' || c == '\t' {
-				continue
-			} else if decodeMap[c] != 0xFF {
-				vals[valCount] = decodeMap[c]
-				valCount++
-			}
-		}
-
-		if valCount < 2 {
-			break
-		}
-
-		if di < len(dst) {
-			dst[di] = vals[0]<<2 | vals[1]>>4
-			di++
-		}
-		if valCount >= 3 && di < len(dst) {
-			dst[di] = vals[1]<<4 | vals[2]>>2
-			di++
-		}
-		if valCount >= 4 && di < len(dst) {
-			dst[di] = vals[2]<<6 | vals[3]
-			di++
-		}
-	}
-
-	return di, nil
-}
-
 func extractAnyCoverArt(filePath string) ([]byte, string, error) {
 	return extractAnyCoverArtWithHint(filePath, "")
 }

go_backend/audio_metadata_supplement_test.go

@@ -164,12 +164,6 @@ func TestAudioMetadataCoverAndQualityHelpers(t *testing.T) {
 	if commentMIME != "image/png" || !bytes.Equal(commentImage, png) {
 		t.Fatalf("vorbis picture = %s/%v", commentMIME, commentImage)
 	}
-	decoded := make([]byte, base64StdDecodeLen(len("SGV sbG8="))+4)
-	n, err := base64StdDecode(decoded, []byte("SGV sbG8="))
-	if err != nil || strings.TrimRight(string(decoded[:n]), "\x00") != "Hello" {
-		t.Fatalf("base64 decode = %q/%v", decoded[:n], err)
-	}
-
 	if detectOggStreamType([][]byte{[]byte("OpusHeadxxxx")}) != oggStreamOpus {
 		t.Fatal("expected opus stream")
 	}

go_backend/extension_goja_convert.go

@@ -57,17 +57,6 @@ func gojaObjectInt64(obj *goja.Object, keys ...string) int64 {
 	return 0
 }
 
-func gojaObjectFloat(obj *goja.Object, keys ...string) float64 {
-	for _, key := range keys {
-		value := obj.Get(key)
-		if gojaValueIsEmpty(value) {
-			continue
-		}
-		return value.ToFloat()
-	}
-	return 0
-}
-
 func gojaObjectBool(obj *goja.Object, keys ...string) bool {
 	for _, key := range keys {
 		value := obj.Get(key)
@@ -467,16 +456,6 @@ func parseExtensionAvailabilityValue(vm *goja.Runtime, value goja.Value) ExtAvai
 	}
 }
 
-func parseExtensionDownloadURLValue(vm *goja.Runtime, value goja.Value) ExtDownloadURLResult {
-	obj := value.ToObject(vm)
-	return ExtDownloadURLResult{
-		URL:        gojaObjectString(obj, "url"),
-		Format:     gojaObjectString(obj, "format"),
-		BitDepth:   gojaObjectInt(obj, "bit_depth", "bitDepth"),
-		SampleRate: gojaObjectInt(obj, "sample_rate", "sampleRate"),
-	}
-}
-
 func parseExtensionDownloadDecryptionValue(vm *goja.Runtime, value goja.Value) *DownloadDecryptionInfo {
 	if gojaValueIsEmpty(value) {
 		return nil
@@ -577,16 +556,6 @@ func parseExtensionURLHandleValue(vm *goja.Runtime, value goja.Value) (ExtURLHan
 	return handleResult, nil
 }
 
-func parseExtensionMatchTrackValue(vm *goja.Runtime, value goja.Value) MatchTrackResult {
-	obj := value.ToObject(vm)
-	return MatchTrackResult{
-		Matched:    gojaObjectBool(obj, "matched"),
-		TrackID:    gojaObjectString(obj, "track_id", "trackId"),
-		Confidence: gojaObjectFloat(obj, "confidence"),
-		Reason:     gojaObjectString(obj, "reason"),
-	}
-}
-
 func parseExtensionPostProcessValue(vm *goja.Runtime, value goja.Value) PostProcessResult {
 	obj := value.ToObject(vm)
 	return PostProcessResult{

go_backend/extension_provider_supplement_test.go

@@ -57,22 +57,14 @@ func TestExtensionProviderWrapperFullSurface(t *testing.T) {
 		t.Fatalf("enriched = %#v", enriched)
 	}
 
-	availability, err := provider.CheckAvailability("ISRC", "Song", "Artist", "spotify:1", "dz", "tidal", "qobuz")
+	availability, err := provider.CheckAvailabilityForItemID("ISRC", "Song", "Artist", "spotify:1", "dz", "tidal", "qobuz", 0, "")
 	if err != nil {
-		t.Fatalf("CheckAvailability: %v", err)
+		t.Fatalf("CheckAvailabilityForItemID: %v", err)
 	}
 	if !availability.Available || availability.TrackID != "download-track" || !availability.SkipFallback {
 		t.Fatalf("availability = %#v", availability)
 	}
 
-	downloadURL, err := provider.GetDownloadURL("track-1", "LOSSLESS")
-	if err != nil {
-		t.Fatalf("GetDownloadURL: %v", err)
-	}
-	if downloadURL.Format != "flac" || downloadURL.BitDepth != 24 || downloadURL.SampleRate != 96000 {
-		t.Fatalf("download URL = %#v", downloadURL)
-	}
-
 	progress := []int{}
 	download, err := provider.Download("track-1", "LOSSLESS", filepath.Join(t.TempDir(), "song.flac"), "", func(percent int) {
 		progress = append(progress, percent)
@@ -100,17 +92,6 @@ func TestExtensionProviderWrapperFullSurface(t *testing.T) {
 		t.Fatalf("url result = %#v", urlResult)
 	}
 
-	match, err := provider.MatchTrack(
-		map[string]any{"name": "Song", "artists": "Artist"},
-		[]map[string]any{{"id": "download-track", "name": "Song"}},
-	)
-	if err != nil {
-		t.Fatalf("MatchTrack: %v", err)
-	}
-	if !match.Matched || match.TrackID != "download-track" {
-		t.Fatalf("match = %#v", match)
-	}
-
 	post, err := provider.PostProcess(filepath.Join(t.TempDir(), "song.flac"), map[string]any{"title": "Song"}, "hook")
 	if err != nil {
 		t.Fatalf("PostProcess: %v", err)

go_backend/extension_provider_types.go

@@ -91,13 +91,6 @@ type ExtAvailabilityResult struct {
 	SkipFallback bool   `json:"skip_fallback,omitempty"`
 }
 
-type ExtDownloadURLResult struct {
-	URL        string `json:"url"`
-	Format     string `json:"format"`
-	BitDepth   int    `json:"bit_depth,omitempty"`
-	SampleRate int    `json:"sample_rate,omitempty"`
-}
-
 type DownloadDecryptionInfo struct {
 	Strategy        string         `json:"strategy,omitempty"`
 	Key             string         `json:"key,omitempty"`

go_backend/extension_provider_wrapper.go

@@ -413,10 +413,6 @@ func (p *extensionProviderWrapper) EnrichTrackForItemID(track *ExtTrackMetadata,
 	return &enrichedTrack, nil
 }
 
-func (p *extensionProviderWrapper) CheckAvailability(isrc, trackName, artistName, spotifyID, deezerID, tidalID, qobuzID string) (*ExtAvailabilityResult, error) {
-	return p.CheckAvailabilityForItemID(isrc, trackName, artistName, spotifyID, deezerID, tidalID, qobuzID, 0, "")
-}
-
 func (p *extensionProviderWrapper) CheckAvailabilityForItemID(isrc, trackName, artistName, spotifyID, deezerID, tidalID, qobuzID string, durationMS int, itemID string) (*ExtAvailabilityResult, error) {
 	if !p.extension.Manifest.IsDownloadProvider() {
 		return nil, fmt.Errorf("extension '%s' is not a download provider", p.extension.ID)
@@ -488,54 +484,6 @@ func (p *extensionProviderWrapper) CheckAvailabilityForItemID(isrc, trackName, a
 	return &availability, nil
 }
 
-func (p *extensionProviderWrapper) GetDownloadURL(trackID, quality string) (*ExtDownloadURLResult, error) {
-	if !p.extension.Manifest.IsDownloadProvider() {
-		return nil, fmt.Errorf("extension '%s' is not a download provider", p.extension.ID)
-	}
-
-	if !p.extension.Enabled {
-		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
-	}
-	perf := newExtensionCallPerf(p.extension.ID, "getDownloadUrl")
-	defer perf.finish()
-	initStartedAt := time.Now()
-	if err := p.lockReadyVM(); err != nil {
-		return nil, err
-	}
-	perf.recordInit(time.Since(initStartedAt))
-	defer p.extension.VMMu.Unlock()
-
-	script := fmt.Sprintf(`
-		(function() {
-			if (typeof extension !== 'undefined' && typeof extension.getDownloadUrl === 'function') {
-				return extension.getDownloadUrl(%q, %q);
-			}
-			return null;
-		})()
-	`, trackID, quality)
-
-	jsStartedAt := time.Now()
-	result, err := RunWithTimeoutAndRecover(p.vm, script, DefaultJSTimeout)
-	perf.recordJS(time.Since(jsStartedAt))
-	perf.recordPayload(result)
-	if err != nil {
-		if IsTimeoutError(err) {
-			return nil, fmt.Errorf("getDownloadUrl timeout: extension took too long to respond")
-		}
-		return nil, fmt.Errorf("getDownloadUrl failed: %w", err)
-	}
-
-	if result == nil || goja.IsUndefined(result) || goja.IsNull(result) {
-		return nil, fmt.Errorf("getDownloadUrl returned null")
-	}
-
-	parseStartedAt := time.Now()
-	urlResult := parseExtensionDownloadURLValue(p.vm, result)
-	perf.recordParse(time.Since(parseStartedAt))
-	perf.setItems(1)
-	return &urlResult, nil
-}
-
 const ExtDownloadTimeout = DownloadTimeout
 
 func (p *extensionProviderWrapper) Download(trackID, quality, outputPath, itemID string, onProgress func(percent int)) (*ExtDownloadResult, error) {
@@ -656,10 +604,6 @@ func (p *extensionProviderWrapper) CustomSearchForRequestID(query string, option
 	return p.customSearch(query, options, "", requestID)
 }
 
-func (p *extensionProviderWrapper) CustomSearchForItemID(query string, options map[string]any, itemID string) ([]ExtTrackMetadata, error) {
-	return p.customSearch(query, options, itemID, "")
-}
-
 func (p *extensionProviderWrapper) customSearch(query string, options map[string]any, itemID, requestID string) ([]ExtTrackMetadata, error) {
 	if !p.extension.Manifest.HasCustomSearch() {
 		return nil, fmt.Errorf("extension '%s' does not support custom search", p.extension.ID)
@@ -875,64 +819,6 @@ func (p *extensionProviderWrapper) HandleURL(url string) (*ExtURLHandleResult, e
 	return &handleResult, nil
 }
 
-type MatchTrackResult struct {
-	Matched    bool    `json:"matched"`
-	TrackID    string  `json:"track_id,omitempty"`
-	Confidence float64 `json:"confidence,omitempty"`
-	Reason     string  `json:"reason,omitempty"`
-}
-
-func (p *extensionProviderWrapper) MatchTrack(sourceTrack map[string]any, candidates []map[string]any) (*MatchTrackResult, error) {
-	if !p.extension.Manifest.HasCustomMatching() {
-		return nil, fmt.Errorf("extension '%s' does not support custom matching", p.extension.ID)
-	}
-
-	if !p.extension.Enabled {
-		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
-	}
-	perf := newExtensionCallPerf(p.extension.ID, "matchTrack")
-	defer perf.finish()
-	initStartedAt := time.Now()
-	if err := p.lockReadyVM(); err != nil {
-		return nil, err
-	}
-	perf.recordInit(time.Since(initStartedAt))
-	defer p.extension.VMMu.Unlock()
-
-	sourceJSON, _ := json.Marshal(sourceTrack)
-	candidatesJSON, _ := json.Marshal(candidates)
-
-	script := fmt.Sprintf(`
-		(function() {
-			if (typeof extension !== 'undefined' && typeof extension.matchTrack === 'function') {
-				return extension.matchTrack(%s, %s);
-			}
-			return null;
-		})()
-	`, string(sourceJSON), string(candidatesJSON))
-
-	jsStartedAt := time.Now()
-	result, err := RunWithTimeoutAndRecover(p.vm, script, DefaultJSTimeout)
-	perf.recordJS(time.Since(jsStartedAt))
-	perf.recordPayload(result)
-	if err != nil {
-		if IsTimeoutError(err) {
-			return nil, fmt.Errorf("matchTrack timeout: extension took too long to respond")
-		}
-		return nil, fmt.Errorf("matchTrack failed: %w", err)
-	}
-
-	if result == nil || goja.IsUndefined(result) || goja.IsNull(result) {
-		return &MatchTrackResult{Matched: false, Reason: "not implemented"}, nil
-	}
-
-	parseStartedAt := time.Now()
-	matchResult := parseExtensionMatchTrackValue(p.vm, result)
-	perf.recordParse(time.Since(parseStartedAt))
-	perf.setItems(1)
-	return &matchResult, nil
-}
-
 type PostProcessResult struct {
 	Success     bool   `json:"success"`
 	NewFilePath string `json:"new_file_path,omitempty"`

go_backend/extension_providers_test.go

@@ -745,15 +745,6 @@ func TestParseExtensionURLHandleResult(t *testing.T) {
 func TestParseExtensionAuxiliaryResults(t *testing.T) {
 	vm := goja.New()
 
-	matchValue, err := vm.RunString(`({ matched: true, trackId: "track-1", confidence: 0.92, reason: "isrc" })`)
-	if err != nil {
-		t.Fatalf("build match value: %v", err)
-	}
-	match := parseExtensionMatchTrackValue(vm, matchValue)
-	if !match.Matched || match.TrackID != "track-1" || match.Confidence != 0.92 || match.Reason != "isrc" {
-		t.Fatalf("unexpected match result: %+v", match)
-	}
-
 	postValue, err := vm.RunString(`({ success: true, newFilePath: "/tmp/new.flac", newFileUri: "content://new", bitDepth: 24, sampleRate: 96000 })`)
 	if err != nil {
 		t.Fatalf("build post-process value: %v", err)

go_backend/httputil.go

@@ -125,11 +125,6 @@ var sharedClient = &http.Client{
 	Timeout:   DefaultTimeout,
 }
 
-var downloadClient = &http.Client{
-	Transport: newCompatibilityTransport(sharedTransport),
-	Timeout:   DownloadTimeout,
-}
-
 func NewHTTPClientWithTimeout(timeout time.Duration) *http.Client {
 	return &http.Client{
 		Transport: newCompatibilityTransport(sharedTransport),
@@ -144,14 +139,6 @@ func NewMetadataHTTPClient(timeout time.Duration) *http.Client {
 	}
 }
 
-func GetSharedClient() *http.Client {
-	return sharedClient
-}
-
-func GetDownloadClient() *http.Client {
-	return downloadClient
-}
-
 func CloseIdleConnections() {
 	sharedTransport.CloseIdleConnections()
 	extensionAPITransport.CloseIdleConnections()
@@ -403,32 +390,6 @@ func ReadResponseBody(resp *http.Response) ([]byte, error) {
 	return body, nil
 }
 
-func ValidateResponse(resp *http.Response) error {
-	if resp == nil {
-		return fmt.Errorf("response is nil")
-	}
-
-	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return fmt.Errorf("HTTP %d: %s", resp.StatusCode, resp.Status)
-	}
-
-	return nil
-}
-
-func BuildErrorMessage(apiURL string, statusCode int, responsePreview string) string {
-	msg := fmt.Sprintf("API %s failed", apiURL)
-	if statusCode > 0 {
-		msg += fmt.Sprintf(" (HTTP %d)", statusCode)
-	}
-	if responsePreview != "" {
-		if len(responsePreview) > 100 {
-			responsePreview = responsePreview[:100] + "..."
-		}
-		msg += fmt.Sprintf(": %s", responsePreview)
-	}
-	return msg
-}
-
 type ISPBlockingError struct {
 	Domain      string
 	Reason      string

go_backend/httputil_supplement_test.go

@@ -26,9 +26,6 @@ func TestHTTPUtilityHelpers(t *testing.T) {
 	if NewHTTPClientWithTimeout(time.Second).Timeout != time.Second || NewMetadataHTTPClient(time.Second).Timeout != time.Second {
 		t.Fatal("client timeout mismatch")
 	}
-	if GetSharedClient() == nil || GetDownloadClient() == nil {
-		t.Fatal("expected shared clients")
-	}
 	if sharedTransport.TLSClientConfig == nil || sharedTransport.TLSClientConfig.RootCAs == nil {
 		t.Fatal("expected supplemental TLS root pool")
 	}
@@ -115,18 +112,6 @@ func TestHTTPUtilityHelpers(t *testing.T) {
 	if body, err := ReadResponseBody(&http.Response{Body: io.NopCloser(strings.NewReader("ok"))}); err != nil || string(body) != "ok" {
 		t.Fatalf("ReadResponseBody = %q/%v", body, err)
 	}
-	if err := ValidateResponse(nil); err == nil {
-		t.Fatal("expected nil response validation error")
-	}
-	if err := ValidateResponse(&http.Response{StatusCode: 404, Status: "404 Not Found"}); err == nil {
-		t.Fatal("expected bad status validation error")
-	}
-	if err := ValidateResponse(&http.Response{StatusCode: 200}); err != nil {
-		t.Fatalf("ValidateResponse: %v", err)
-	}
-	if msg := BuildErrorMessage("api", 500, strings.Repeat("x", 120)); !strings.Contains(msg, "...") {
-		t.Fatalf("BuildErrorMessage = %q", msg)
-	}
 	if calculateNextDelay(10*time.Millisecond, RetryConfig{BackoffFactor: 3, MaxDelay: 20 * time.Millisecond}) != 20*time.Millisecond {
 		t.Fatal("calculateNextDelay mismatch")
 	}

go_backend/misc_coverage_supplement_test.go

@@ -227,8 +227,8 @@ func TestExtensionHealthInitializeVMAndCustomSearchWrappers(t *testing.T) {
 	cancelMu.Lock()
 	delete(cancelMap, "custom-item-unique")
 	cancelMu.Unlock()
-	if tracks, err := provider.CustomSearchForItemID("needle", nil, "custom-item-unique"); err != nil || len(tracks) == 0 {
-		t.Fatalf("CustomSearchForItemID = %#v/%v", tracks, err)
+	if tracks, err := provider.customSearch("needle", nil, "custom-item-unique", ""); err != nil || len(tracks) == 0 {
+		t.Fatalf("customSearch (item ID) = %#v/%v", tracks, err)
 	}
 	if healthJSON, err := CheckExtensionHealthJSON(ext.ID); err != nil || !strings.Contains(healthJSON, `"status":"offline"`) {
 		t.Fatalf("CheckExtensionHealthJSON = %q/%v", healthJSON, err)

lib/screens/album_screen.dart

@@ -455,7 +455,6 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen> {
         controller: _scrollController,
         slivers: [
           _buildAppBar(context, colorScheme, pageBackgroundColor),
-          _buildInfoCard(context, colorScheme),
           if (_isLoading)
             const SliverToBoxAdapter(
               child: Padding(
@@ -628,10 +627,6 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen> {
     );
   }
 
-  Widget _buildInfoCard(BuildContext context, ColorScheme colorScheme) {
-    return const SliverToBoxAdapter(child: SizedBox.shrink());
-  }
-
   Widget _buildAlbumFooter(
     BuildContext context,
     ColorScheme colorScheme,

lib/screens/downloaded_album_screen.dart

@@ -395,7 +395,6 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
               controller: _scrollController,
               slivers: [
                 _buildAppBar(context, colorScheme, tracks),
-                _buildInfoCard(context, colorScheme, tracks),
                 _buildTrackList(context, colorScheme, tracks),
                 SliverToBoxAdapter(
                   child: SizedBox(height: _isSelectionMode ? 120 : 32),
@@ -639,14 +638,6 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
     );
   }
 
-  Widget _buildInfoCard(
-    BuildContext context,
-    ColorScheme colorScheme,
-    List<DownloadHistoryItem> tracks,
-  ) {
-    return const SliverToBoxAdapter(child: SizedBox.shrink());
-  }
-
   String? _getCommonQuality(List<DownloadHistoryItem> tracks) {
     if (identical(tracks, _commonQualitySourceCache)) {
       return _commonQualityCache;

lib/screens/local_album_screen.dart

@@ -283,7 +283,6 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
               controller: _scrollController,
               slivers: [
                 _buildAppBar(context, colorScheme),
-                _buildInfoCard(context, colorScheme, tracks),
                 _buildTrackList(context, colorScheme, tracks),
                 SliverToBoxAdapter(
                   child: SizedBox(height: _isSelectionMode ? 120 : 32),
@@ -385,14 +384,6 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
     );
   }
 
-  Widget _buildInfoCard(
-    BuildContext context,
-    ColorScheme colorScheme,
-    List<LocalLibraryItem> tracks,
-  ) {
-    return const SliverToBoxAdapter(child: SizedBox.shrink());
-  }
-
   Widget _metaWhiteItem(IconData? icon, String label) {
     const textStyle = TextStyle(
       color: Colors.white,

lib/screens/main_shell.dart

@@ -812,60 +812,6 @@ class _SlidingIconState extends State<SlidingIcon>
   }
 }
 
-class SwingIcon extends StatefulWidget {
-  final Widget child;
-  const SwingIcon({super.key, required this.child});
-
-  @override
-  State<SwingIcon> createState() => _SwingIconState();
-}
-
-class _SwingIconState extends State<SwingIcon>
-    with SingleTickerProviderStateMixin {
-  late AnimationController _controller;
-  late Animation<double> _rotationAnimation;
-
-  @override
-  void initState() {
-    super.initState();
-    _controller = AnimationController(
-      duration: const Duration(milliseconds: 600),
-      vsync: this,
-    );
-
-    _rotationAnimation = TweenSequence<double>([
-      TweenSequenceItem(tween: Tween(begin: 0.0, end: -0.2), weight: 20),
-      TweenSequenceItem(tween: Tween(begin: -0.2, end: 0.15), weight: 20),
-      TweenSequenceItem(tween: Tween(begin: 0.15, end: -0.1), weight: 20),
-      TweenSequenceItem(tween: Tween(begin: -0.1, end: 0.05), weight: 20),
-      TweenSequenceItem(tween: Tween(begin: 0.05, end: 0.0), weight: 20),
-    ]).animate(_controller);
-
-    _controller.forward();
-  }
-
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return AnimatedBuilder(
-      animation: _rotationAnimation,
-      builder: (context, child) {
-        return Transform.rotate(
-          angle: _rotationAnimation.value,
-          alignment: Alignment.topCenter,
-          child: child,
-        );
-      },
-      child: widget.child,
-    );
-  }
-}
-
 class SpinIcon extends StatefulWidget {
   final Widget child;
   const SpinIcon({super.key, required this.child});

lib/screens/playlist_screen.dart

@@ -202,7 +202,6 @@ class _PlaylistScreenState extends ConsumerState<PlaylistScreen> {
         controller: _scrollController,
         slivers: [
           _buildAppBar(context, colorScheme),
-          _buildInfoCard(context, colorScheme),
           _buildTrackList(context, colorScheme),
           _buildPlaylistFooter(context, colorScheme),
           SliverToBoxAdapter(
@@ -296,10 +295,6 @@ class _PlaylistScreenState extends ConsumerState<PlaylistScreen> {
     );
   }
 
-  Widget _buildInfoCard(BuildContext context, ColorScheme colorScheme) {
-    return const SliverToBoxAdapter(child: SizedBox.shrink());
-  }
-
   String _formatReleaseDate(String date) {
     if (date.length >= 10) {
       final parts = date.substring(0, 10).split('-');

lib/widgets/animation_utils.dart

@@ -56,34 +56,6 @@ class StaggeredListItem extends StatelessWidget {
   }
 }
 
-/// A convenience wrapper around [AnimatedSwitcher] that crossfades between
-/// different widget states (loading, content, empty, error).
-///
-/// Assign a unique [ValueKey] to each child so the switcher detects changes.
-class AnimatedStateSwitcher extends StatelessWidget {
-  final Widget child;
-  final Duration duration;
-
-  const AnimatedStateSwitcher({
-    super.key,
-    required this.child,
-    this.duration = const Duration(milliseconds: 250),
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    return AnimatedSwitcher(
-      duration: duration,
-      switchInCurve: Curves.easeOut,
-      switchOutCurve: Curves.easeIn,
-      transitionBuilder: (child, animation) {
-        return FadeTransition(opacity: animation, child: child);
-      },
-      child: child,
-    );
-  }
-}
-
 /// Creates a platform-aware material route.
 ///
 /// This intentionally defers route transitions to Flutter's material route and
@@ -93,58 +65,6 @@ Route<T> slidePageRoute<T>({required Widget page}) {
   return MaterialPageRoute<T>(builder: (context) => page);
 }
 
-/// A directional horizontal transition for adjacent content, such as moving
-/// between next/previous items within the same detail context.
-Route<T> adjacentHorizontalPageRoute<T>({
-  required Widget page,
-  required bool fromRight,
-}) {
-  return _AdjacentHorizontalPageRoute<T>(
-    builder: (context) => page,
-    fromRight: fromRight,
-  );
-}
-
-class _AdjacentHorizontalPageRoute<T> extends MaterialPageRoute<T> {
-  final bool fromRight;
-
-  _AdjacentHorizontalPageRoute({
-    required super.builder,
-    required this.fromRight,
-  });
-
-  @override
-  Widget buildTransitions(
-    BuildContext context,
-    Animation<double> animation,
-    Animation<double> secondaryAnimation,
-    Widget child,
-  ) {
-    if (animation.status == AnimationStatus.reverse) {
-      return super.buildTransitions(
-        context,
-        animation,
-        secondaryAnimation,
-        child,
-      );
-    }
-
-    final curved = CurvedAnimation(
-      parent: animation,
-      curve: Curves.easeOutCubic,
-    );
-    final begin = Offset(fromRight ? 0.22 : -0.22, 0);
-
-    return SlideTransition(
-      position: Tween<Offset>(begin: begin, end: Offset.zero).animate(curved),
-      child: FadeTransition(
-        opacity: Tween<double>(begin: 0.92, end: 1.0).animate(curved),
-        child: child,
-      ),
-    );
-  }
-}
-
 /// A shimmer effect widget that can wrap skeleton placeholders.
 class ShimmerLoading extends StatefulWidget {
   final Widget child;
@@ -331,8 +251,6 @@ class TrackListSkeleton extends StatelessWidget {
   }
 }
 
-/// Grid skeleton – mimics a grid of album/playlist cards while loading.
-
 /// Album track list skeleton – mimics the album screen track list layout
 /// (track number + title + artist + trailing icon, no cover art thumbnail).
 class AlbumTrackListSkeleton extends StatelessWidget {
@@ -470,59 +388,6 @@ class _CollectionHeaderSkeleton extends StatelessWidget {
   }
 }
 
-class GridSkeleton extends StatelessWidget {
-  final int itemCount;
-  final int crossAxisCount;
-
-  const GridSkeleton({super.key, this.itemCount = 6, this.crossAxisCount = 2});
-
-  @override
-  Widget build(BuildContext context) {
-    return ShimmerLoading(
-      child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 16),
-        child: GridView.builder(
-          shrinkWrap: true,
-          physics: const NeverScrollableScrollPhysics(),
-          gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
-            crossAxisCount: crossAxisCount,
-            mainAxisSpacing: 12,
-            crossAxisSpacing: 12,
-            childAspectRatio: 0.75,
-          ),
-          itemCount: itemCount,
-          itemBuilder: (context, index) {
-            return Column(
-              crossAxisAlignment: CrossAxisAlignment.start,
-              children: [
-                const Expanded(
-                  child: SkeletonBox(
-                    width: double.infinity,
-                    height: double.infinity,
-                    borderRadius: 12,
-                  ),
-                ),
-                const SizedBox(height: 8),
-                SkeletonBox(
-                  width: 80 + (index % 3) * 20,
-                  height: 12,
-                  borderRadius: 4,
-                ),
-                const SizedBox(height: 4),
-                SkeletonBox(
-                  width: 50 + (index % 2) * 15,
-                  height: 10,
-                  borderRadius: 4,
-                ),
-              ],
-            );
-          },
-        ),
-      ),
-    );
-  }
-}
-
 /// Artist screen skeleton shown below the SliverAppBar header while the
 /// discography loads: optional cover placeholder, "Popular" section, and the
 /// horizontal album sections.
@@ -939,15 +804,3 @@ class _AnimatedBadgeState extends State<AnimatedBadge>
     return ScaleTransition(scale: _scaleAnimation, child: widget.child);
   }
 }
-
-/// Build a removal animation for [AnimatedList] items.
-/// Use as the `builder` callback in [AnimatedListState.removeItem].
-Widget buildRemovalAnimation(Widget child, Animation<double> animation) {
-  return SizeTransition(
-    sizeFactor: CurvedAnimation(parent: animation, curve: Curves.easeInOut),
-    child: FadeTransition(
-      opacity: CurvedAnimation(parent: animation, curve: Curves.easeIn),
-      child: child,
-    ),
-  );
-}

lib/widgets/bottom_sheet_option_tile.dart

@@ -1,40 +0,0 @@
-import 'package:flutter/material.dart';
-
-/// Reusable option tile for bottom sheets.
-/// Used in playlist options, track options, cover options, etc.
-class BottomSheetOptionTile extends StatelessWidget {
-  final IconData icon;
-  final Color? iconColor;
-  final String title;
-  final VoidCallback onTap;
-
-  const BottomSheetOptionTile({
-    super.key,
-    required this.icon,
-    this.iconColor,
-    required this.title,
-    required this.onTap,
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    return ListTile(
-      contentPadding: const EdgeInsets.symmetric(horizontal: 24, vertical: 4),
-      leading: Container(
-        padding: const EdgeInsets.all(10),
-        decoration: BoxDecoration(
-          color: colorScheme.primaryContainer,
-          borderRadius: BorderRadius.circular(12),
-        ),
-        child: Icon(
-          icon,
-          color: iconColor ?? colorScheme.onPrimaryContainer,
-          size: 20,
-        ),
-      ),
-      title: Text(title, style: const TextStyle(fontWeight: FontWeight.w500)),
-      onTap: onTap,
-    );
-  }
-}

pubspec.lock

@@ -281,14 +281,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.2.1"
-  code_builder:
-    dependency: transitive
-    description:
-      name: code_builder
-      sha256: "6a6cab2ba4680d6423f34a9b972a4c9a94ebe1b62ecec4e1a1f2cba91fd1319d"
-      url: "https://pub.dev"
-    source: hosted
-    version: "4.11.1"
   collection:
     dependency: transitive
     description:
@@ -829,14 +821,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
-  mockito:
-    dependency: transitive
-    description:
-      name: mockito
-      sha256: eff30d002f0c8bf073b6f929df4483b543133fcafce056870163587b03f1d422
-      url: "https://pub.dev"
-    source: hosted
-    version: "5.6.4"
   nm:
     dependency: transitive
     description:
@@ -1077,22 +1061,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.0-dev.10"
-  riverpod_annotation:
-    dependency: transitive
-    description:
-      name: riverpod_annotation
-      sha256: "674dbb26e2db3d9253166faf4758c796af14146b8fbcf5e7102bc8a04cd359b8"
-      url: "https://pub.dev"
-    source: hosted
-    version: "4.0.3"
-  riverpod_generator:
-    dependency: "direct dev"
-    description:
-      name: riverpod_generator
-      sha256: "54d790c3fee1ae281c448801bfdbfaa9fd961a9d3998494e0fcd9ee32184d7eb"
-      url: "https://pub.dev"
-    source: hosted
-    version: "4.0.4"
   riverpod_lint:
     dependency: "direct dev"
     description:

pubspec.yaml

@@ -74,7 +74,6 @@ dev_dependencies:
     sdk: flutter
   flutter_lints: ^6.0.0
   build_runner: ^2.15.0
-  riverpod_generator: ^4.0.4
   riverpod_lint: ^3.1.4
   json_serializable: ^6.14.0
   flutter_launcher_icons: ^0.14.3