chore: 更新知识库文章发布日期

- 将所有文章的发布日期从2023年更新至2025年12月
- 确保内容时效性，提升用户体验

campus_health_app/frontend/campus-health-app/src/app/modules/knowledge/knowledge.component.ts

@@ -50,7 +50,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'fitness',
       summary: '了解如何根据个人目标和身体状况，制定科学合理的健身计划，提高训练效果。',
       readTime: 8,
-      publishDate: '2023-10-15',
+      publishDate: '2025-12-15',
       author: '健身专家张教练',
       isFeatured: true,
       tags: ['训练计划', '科学健身', '个性化']
@@ -61,7 +61,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'nutrition',
       summary: '运动后的营养补充对于肌肉修复和体能恢复至关重要，本文将为您详细介绍最佳的营养补充时机和方案。',
       readTime: 6,
-      publishDate: '2023-10-10',
+      publishDate: '2025-12-10',
       author: '营养师李医生',
       isFeatured: true,
       tags: ['营养补充', '肌肉修复', '体能恢复']
@@ -76,7 +76,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'fitness',
       summary: '新手健身时容易陷入一些误区，了解这些误区并学会避免，可以让您的健身之路更加顺畅。',
       readTime: 5,
-      publishDate: '2023-10-08',
+      publishDate: '2025-12-08',
       author: '健身顾问王教练',
       isFeatured: false,
       tags: ['新手健身', '常见误区', '健身技巧']
@@ -87,7 +87,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'recovery',
       summary: '充足的睡眠是肌肉修复和体能恢复的关键，了解如何提高睡眠质量，让健身效果事半功倍。',
       readTime: 7,
-      publishDate: '2023-10-05',
+      publishDate: '2025-12-08',
       author: '健康管理师陈医生',
       isFeatured: false,
       tags: ['睡眠质量', '肌肉修复', '体能恢复']
@@ -98,7 +98,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'lifestyle',
       summary: '健身期间保持充足的水分摄入对于维持身体机能和提高训练效果非常重要，本文将为您提供科学的饮水建议。',
       readTime: 4,
-      publishDate: '2023-10-01',
+      publishDate: '2025-12-08',
       author: '健康顾问林教练',
       isFeatured: false,
       tags: ['饮水指南', '健身期间', '身体机能']
@@ -109,7 +109,7 @@ export class KnowledgeComponent implements OnInit {
       categoryId: 'nutrition',
       summary: '增肌、减脂、维持体型等不同的健身目标需要不同的营养策略，了解这些策略，让您的健身事半功倍。',
       readTime: 9,
-      publishDate: '2023-09-28',
+      publishDate: '2025-12-08',
       author: '营养师赵医生',
       isFeatured: false,
       tags: ['营养策略', '增肌', '减脂']