feat(ui): 更新品牌启动页与选集交互

lib/pages/player/widgets/episode_picker_cell.dart

@@ -0,0 +1,116 @@
+// Author: fruit.com.cn
+
+import 'package:flutter/material.dart';
+
+import '../../../core/data/models/drama.dart';
+import '../../../core/theme/app_colors.dart';
+
+const double _cellRadius = 8;
+const double _numberSize = 15;
+const double _lockSize = 16;
+const double _lockGap = 4;
+const double _lockWeight = 300;
+const double _coverAlpha = 0.45;
+
+/// 选集格子。需要解锁时铺一层透明底，锁在上，集数在锁下面。
+class EpisodePickerCell extends StatelessWidget {
+  const EpisodePickerCell({
+    required this.episode,
+    required this.selected,
+    required this.lockLabel,
+    required this.onTap,
+    super.key,
+  });
+
+  final Episode episode;
+  final bool selected;
+  final String lockLabel;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    return Material(
+      clipBehavior: Clip.antiAlias,
+      color: selected ? AppColors.bluePressed : AppColors.raised,
+      borderRadius: BorderRadius.circular(_cellRadius),
+      child: InkWell(
+        onTap: onTap,
+        child: Stack(
+          fit: StackFit.expand,
+          children: [
+            if (!episode.locked) Center(child: _EpisodeNumber(episode.number)),
+            if (episode.locked)
+              _LockCover(
+                episodeId: episode.id,
+                number: episode.number,
+                label: lockLabel,
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _EpisodeNumber extends StatelessWidget {
+  const _EpisodeNumber(this.number);
+
+  final int number;
+
+  @override
+  Widget build(BuildContext context) {
+    return Text(
+      '$number',
+      style: const TextStyle(
+        color: AppColors.cream,
+        fontSize: _numberSize,
+        fontWeight: FontWeight.w600,
+        height: 1,
+      ),
+    );
+  }
+}
+
+/// 透明底铺满格子，锁在上，集数在锁下面。
+class _LockCover extends StatelessWidget {
+  const _LockCover({
+    required this.episodeId,
+    required this.number,
+    required this.label,
+  });
+
+  final String episodeId;
+  final int number;
+  final String label;
+
+  @override
+  Widget build(BuildContext context) {
+    return Stack(
+      fit: StackFit.expand,
+      children: [
+        ColoredBox(
+          key: ValueKey('episode-lock-cover-$episodeId'),
+          color: AppColors.ink.withValues(alpha: _coverAlpha),
+        ),
+        Center(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Icon(
+                Icons.lock_outline,
+                key: ValueKey('episode-lock-$episodeId'),
+                size: _lockSize,
+                weight: _lockWeight,
+                fill: 0,
+                color: AppColors.gold,
+                semanticLabel: label,
+              ),
+              const SizedBox(height: _lockGap),
+              _EpisodeNumber(number),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+}