feat(recite): 完成背诵模块基础框架与核心页面开发

本次提交实现了背诵模块的完整基础链路：
1. 新增词书、背单词接口层与对应数据模型
2. 完成背诵首页、章节列表页等核心页面开发
3. 实现音频播放、加载弹窗等通用组件
4. 配置路由跳转链路，替换旧版缓存传参方案
5. 对齐Vue端业务逻辑与UI样式

lib/features/recite/widgets/recite_circle_progress.dart

@@ -0,0 +1,108 @@
+import 'dart:math' as math;
+
+import 'package:flutter/material.dart';
+import 'package:flutter_screenutil/flutter_screenutil.dart';
+
+/// ============================================================
+/// 【ReciteCircleProgress】圆环进度 —— 对标 Vue l-circle（canvas）
+///
+/// 用在：
+///   1. 章节页右上角「总进度」（顺时针，绿色 #1BC26E，底 #EBEBEB）
+///   2. 学习小结正确率（Vue :clockwise="false"，逆时针绘制，视觉对称）
+///
+/// percent：0~100；中间内容由 child 自定义。
+/// ============================================================
+class ReciteCircleProgress extends StatelessWidget {
+  const ReciteCircleProgress({
+    super.key,
+    required this.percent,
+    required this.size,
+    this.strokeWidth = 4,
+    this.color = const Color(0xFF1BC26E),
+    this.trailColor = const Color(0xFFEBEBEB),
+    this.clockwise = true,
+    this.child,
+  });
+
+  final double percent;
+  final double size; // 直径
+  final double strokeWidth;
+  final Color color;
+  final Color trailColor;
+
+  /// false = 逆时针起笔（对标 l-circle :clockwise="false"）
+  final bool clockwise;
+  final Widget? child;
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox(
+      width: size.w,
+      height: size.w,
+      child: CustomPaint(
+        painter: _CirclePainter(
+          percent: percent.clamp(0, 100).toDouble(),
+          strokeWidth: strokeWidth.w,
+          color: color,
+          trailColor: trailColor,
+          clockwise: clockwise,
+        ),
+        child: Center(child: child),
+      ),
+    );
+  }
+}
+
+class _CirclePainter extends CustomPainter {
+  _CirclePainter({
+    required this.percent,
+    required this.strokeWidth,
+    required this.color,
+    required this.trailColor,
+    required this.clockwise,
+  });
+
+  final double percent;
+  final double strokeWidth;
+  final Color color;
+  final Color trailColor;
+  final bool clockwise;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final center = Offset(size.width / 2, size.height / 2);
+    final radius = (size.width - strokeWidth) / 2;
+
+    final trackPaint =
+        Paint()
+          ..style = PaintingStyle.stroke
+          ..strokeWidth = strokeWidth
+          ..color = trailColor;
+
+    final progressPaint =
+        Paint()
+          ..style = PaintingStyle.stroke
+          ..strokeWidth = strokeWidth
+          ..strokeCap = StrokeCap.round
+          ..color = color;
+
+    canvas.drawCircle(center, radius, trackPaint);
+
+    const start = -math.pi / 2; // 12 点方向
+    final sweep = 2 * math.pi * percent / 100;
+    canvas.drawArc(
+      Rect.fromCircle(center: center, radius: radius),
+      clockwise ? start : start - sweep,
+      sweep,
+      false,
+      progressPaint,
+    );
+  }
+
+  @override
+  bool shouldRepaint(covariant _CirclePainter old) =>
+      old.percent != percent ||
+      old.strokeWidth != strokeWidth ||
+      old.color != color ||
+      old.clockwise != clockwise;
+}