refactor(ui): Lucide migration unit 2 — Icons.* -> LucideIcons.* sweep (#60)

Mechanical sweep across 30 files: every Material Icons.* replaced with
the signed-off Lucide equivalent + a flutter_lucide import per file.
Zero Material Icons.* remain in lib/; no unused imports.

Judgment-call mappings: album->disc_3, library_music->library_big,
playlist_play->list_video, graphic_eq->audio_lines,
system_update->download, restore->archive_restore,
download_done->circle_check_big.

track_actions_sheet like menu row: collapsed `liked ? favorite :
favorite_border` to a single LucideIcons.heart (the row's Like/Unlike
text label conveys state). Icon-only LikeButton + the notification keep
the filled-vs-outline shape per the design decision.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

flutter_client/lib/shared/widgets/track_actions/add_to_playlist_sheet.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_lucide/flutter_lucide.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../../../playlists/playlists_provider.dart';
@@ -70,7 +71,7 @@ class AddToPlaylistSheet extends ConsumerWidget {
                       final p = owned[i];
                       return ListTile(
                         key: Key('add_to_playlist_${p.id}'),
-                        leading: Icon(Icons.queue_music, color: fs.parchment),
+                        leading: Icon(LucideIcons.list_music, color: fs.parchment),
                         title: Text(
                           p.name,
                           style: TextStyle(color: fs.parchment),

flutter_client/lib/shared/widgets/track_actions/track_actions_button.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_lucide/flutter_lucide.dart';
 
 import '../../../models/track.dart';
 import '../../../theme/theme_extension.dart';
@@ -29,7 +30,7 @@ class TrackActionsButton extends StatelessWidget {
   Widget build(BuildContext context) {
     final fs = Theme.of(context).extension<FabledSwordTheme>()!;
     return IconButton(
-      icon: Icon(Icons.more_vert, color: fs.ash, size: 18),
+      icon: Icon(LucideIcons.ellipsis_vertical, color: fs.ash, size: 18),
       tooltip: 'Track actions',
       onPressed: () => TrackActionsSheet.show(
         context,

flutter_client/lib/shared/widgets/track_actions/track_actions_sheet.dart

@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart' as drift;
 import 'package:flutter/material.dart';
+import 'package:flutter_lucide/flutter_lucide.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 
@@ -73,7 +74,7 @@ class TrackActionsSheet extends ConsumerWidget {
             if (!hideQueueActions) ...[
               _MenuItem(
                 key: const Key('track_actions_play_next'),
-                icon: Icons.playlist_play,
+                icon: LucideIcons.list_video,
                 label: 'Play next',
                 onTap: () async {
                   Navigator.pop(context);
@@ -87,7 +88,7 @@ class TrackActionsSheet extends ConsumerWidget {
               ),
               _MenuItem(
                 key: const Key('track_actions_enqueue'),
-                icon: Icons.queue_music,
+                icon: LucideIcons.list_music,
                 label: 'Add to queue',
                 onTap: () async {
                   Navigator.pop(context);
@@ -103,7 +104,7 @@ class TrackActionsSheet extends ConsumerWidget {
             ],
             _MenuItem(
               key: const Key('track_actions_like'),
-              icon: liked ? Icons.favorite : Icons.favorite_border,
+              icon: LucideIcons.heart,
               label: liked ? 'Unlike' : 'Like',
               onTap: () async {
                 Navigator.pop(context);
@@ -112,7 +113,7 @@ class TrackActionsSheet extends ConsumerWidget {
             ),
             _MenuItem(
               key: const Key('track_actions_add_to_playlist'),
-              icon: Icons.playlist_add,
+              icon: LucideIcons.list_plus,
               label: 'Add to playlist…',
               onTap: () async {
                 Navigator.pop(context);
@@ -136,7 +137,7 @@ class TrackActionsSheet extends ConsumerWidget {
             ),
             _MenuItem(
               key: const Key('track_actions_start_radio'),
-              icon: Icons.radio,
+              icon: LucideIcons.radio,
               label: 'Start radio',
               onTap: () async {
                 Navigator.pop(context);
@@ -154,7 +155,7 @@ class TrackActionsSheet extends ConsumerWidget {
             const _Divider(),
             _MenuItem(
               key: const Key('track_actions_go_to_album'),
-              icon: Icons.album,
+              icon: LucideIcons.disc_3,
               label: 'Go to album',
               onTap: () {
                 Navigator.pop(context);
@@ -168,7 +169,7 @@ class TrackActionsSheet extends ConsumerWidget {
             ),
             _MenuItem(
               key: const Key('track_actions_go_to_artist'),
-              icon: Icons.person,
+              icon: LucideIcons.user,
               label: 'Go to artist',
               onTap: () {
                 Navigator.pop(context);
@@ -183,7 +184,7 @@ class TrackActionsSheet extends ConsumerWidget {
             const _Divider(),
             _MenuItem(
               key: const Key('track_actions_hide'),
-              icon: hidden ? Icons.visibility : Icons.visibility_off,
+              icon: hidden ? LucideIcons.eye : LucideIcons.eye_off,
               label: hidden ? 'Unhide' : 'Hide',
               onTap: () async {
                 Navigator.pop(context);