Enhance mini program environment configuration and chapter loading logic

- Introduced a debugging environment configuration in app.js, allowing for dynamic API endpoint selection based on the environment.
- Implemented lazy loading for chapter parts in chapters.js, improving performance by only fetching necessary data.
- Updated UI elements in chapters.wxml to reflect changes in chapter loading and added loading indicators.
- Enhanced error handling and data management for chapter retrieval, ensuring a smoother user experience.
- Added functionality for switching API environments in settings.js, visible only in development mode.

miniprogram/pages/read/read.wxml

@@ -85,10 +85,10 @@
         <!-- 分享操作区 -->
         <view class="action-section">
           <view class="action-row-inline">
-            <button class="action-btn-inline btn-share-inline" open-type="shareTimeline">
+            <view class="action-btn-inline btn-share-inline" bindtap="onShareTimelineTap">
               <text class="action-icon-small">📣</text>
               <text class="action-text-small">分享到朋友圈</text>
-            </button>
+            </view>
             <view class="action-btn-inline btn-poster-inline" bindtap="generatePoster">
               <text class="action-icon-small">🖼️</text>
               <text class="action-text-small">生成海报</text>