feat: v1.5 — plan editor, voice prompts, UI polish

Major features:
- Training plan editor: edit preset days/duration per plan (in-place
  override via custom_plans storage; preset ids preserved so existing
  records stay valid)
- Voice prompts at 4 fixed points during training (halfway / 30s /
  10s / done) via Tencent Cloud TTS (cloudfunctions/tts + utils/voice.js)
- Free-training button: switched from outline (transparent) to ghost
  variant (theme-tinted) for visual weight

Bug fixes:
- 4 functional pages: SVG data URIs failed to render in WeChat because
  '\#' in colors was parsed as a data-URI fragment delimiter. encode the
  whole SVG via encodeURIComponent in utils/icons.js build().
- Old records (saved before id field was added) could not be deleted
  (data-id was empty, triggered defensive guard). Backfill stable
  legacy-<month>-<index>-<duration> ids in getRecords() and persist.
- settings.js plan-row editor button event was bubbling up to the row's
  bindtap (which also fired onSelectPlan). Wrapped in catch:tap.

UI:
- Settings page: 3 hardcoded plans replaced with dynamic buildPlansList
  that overlays custom_plans on top of presets
- Plan editor: bottom-sheet modal in settings page (regular view, not
  ui-modal — WeChat custom component root element drops position:fixed
  in this runtime)
- Free-training button: rounded pill style, full-width, 24rpx gap from
  primary action; bottom sheet uses max-height: 88vh + internal scroll
- Version bumped to v1.5, last updated 2026-06-10

Removed:
- Daily reminder section (dailyReminder / reminderTime) — replaced by
  the 4 voice prompts which cover the same user need without requiring
  long-term scheduling that WeChat mini-programs can't actually do

Misc:
- utils/plan.js refactored to formula-driven: presets declare
  totalDays/startTarget/increment/cycleDays, days[] is generated. Same
  formula applies to custom plans.
- Timer _remind() guards each prompt on minimum duration so short
  free-mode sessions don't fire 'last30' at the start
- Cloud storage cloud_plans field added to data push payload; restored
  on first install via _restoreFromCloud
- .gitignore added for local AI tool caches (.reasonix/, reasonix.toml,
  .codegraph/daemon.pid)

pages/leaderboard/leaderboard.wxml

@@ -0,0 +1,57 @@
+<view class="container" style="{{themeStyle}}">
+  <!-- Period tabs -->
+  <view class="period-tabs">
+    <view
+      wx:for="{{periods}}"
+      wx:key="key"
+      class="period-tab {{activePeriod === item.key ? 'active' : ''}}"
+      data-period="{{item.key}}"
+      bindtap="switchPeriod"
+    >{{item.label}}</view>
+  </view>
+
+  <!-- Loading -->
+  <view class="status-wrap" wx:if="{{loading}}">
+    <text class="status-text">加载中...</text>
+  </view>
+
+  <!-- Empty -->
+  <view class="status-wrap" wx:elif="{{empty}}">
+    <image class="empty-icon" src="{{icons.peopleFill}}" mode="aspectFit"></image>
+    <text class="empty-text">暂无排行数据</text>
+    <text class="empty-sub">快去训练吧!</text>
+  </view>
+
+  <!-- Rank list -->
+  <view class="rank-list" wx:else>
+    <view
+      wx:for="{{rankedList}}"
+      wx:key="openid"
+      class="rank-item {{item.openid === myEntry.openid ? 'is-me' : ''}}"
+    >
+      <view class="rank-num {{item.rank === 1 ? 'gold' : item.rank === 2 ? 'silver' : item.rank === 3 ? 'bronze' : ''}}">
+        <text wx:if="{{item.rank === 1}}">🥇</text>
+        <text wx:elif="{{item.rank === 2}}">🥈</text>
+        <text wx:elif="{{item.rank === 3}}">🥉</text>
+        <text wx:else>{{item.rank}}</text>
+      </view>
+      <image class="rank-avatar" src="{{icons.peopleFill}}" mode="aspectFit"></image>
+      <view class="rank-info">
+        <text class="rank-name">{{item.name}}</text>
+        <text class="rank-sessions">{{item.sessions}}次</text>
+      </view>
+      <text class="rank-dur">{{item.durationText}}</text>
+    </view>
+  </view>
+
+  <!-- My entry pinned at bottom (if not already in list) -->
+  <view class="my-bar" wx:if="{{myEntry && myEntry.rank > rankedList.length}}">
+    <view class="rank-num">{{myEntry.rank}}</view>
+    <image class="rank-avatar" src="{{icons.peopleFill}}" mode="aspectFit"></image>
+    <view class="rank-info">
+      <text class="rank-name">我 ({{myEntry.name}})</text>
+      <text class="rank-sessions">{{myEntry.sessions}}次</text>
+    </view>
+    <text class="rank-dur">{{myEntry.durationText}}</text>
+  </view>
+</view>