perf: 并行加载首页统计数据

将原来顺序执行的4个API调用改为并行执行(Promise.all)，
显著减少首页加载时间。同时提取了渲染函数 renderWeeklyChart、
renderBossRankingPreview、renderPartnerRankingPreview，提高代码复用性。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/js/stats.js

@@ -1,8 +1,15 @@
 async function loadStats() {
   try {
-    const res = await fetch(API + '/api/stats/monthly?year=' + currentYear + '&month=' + currentMonth, { headers: headers() });
-    if (!res.ok) return;
-    const s = await res.json();
+    // 并行加载所有数据
+    const [monthlyRes, bossRankRes, partnerRankRes, weeklyRes] = await Promise.all([
+      fetch(API + '/api/stats/monthly?year=' + currentYear + '&month=' + currentMonth, { headers: headers() }),
+      fetch(API + '/api/stats/boss-ranking/preview?year=' + currentYear + '&month=' + currentMonth, { headers: headers() }),
+      fetch(API + '/api/stats/partner-ranking/preview?year=' + currentYear + '&month=' + currentMonth, { headers: headers() }),
+      fetch(API + '/api/stats/daily-income', { headers: headers() })
+    ]);
+
+    if (monthlyRes.ok) {
+      const s = await monthlyRes.json();
       document.getElementById('takeCount').textContent = s.take_order_count;
       document.getElementById('dispatchCount').textContent = s.dispatch_order_count;
       document.getElementById('takeIncome').textContent = '' + s.take_order_income.toFixed(2);
@@ -14,9 +21,22 @@ async function loadStats() {
       document.getElementById('totalIncome').textContent = '' + s.total_income.toFixed(2);
       document.getElementById('totalExpense').textContent = '' + s.total_expense.toFixed(2);
       document.getElementById('netIncome').textContent = '' + (s.total_income - s.total_expense).toFixed(2);
-    loadBossRankingPreview();
-    loadPartnerRankingPreview();
-    loadWeeklyChart();
+    }
+
+    if (bossRankRes.ok) {
+      const data = await bossRankRes.json();
+      renderBossRankingPreview(data.rows || []);
+    }
+
+    if (partnerRankRes.ok) {
+      const data = await partnerRankRes.json();
+      renderPartnerRankingPreview(data.rows || []);
+    }
+
+    if (weeklyRes.ok) {
+      const days = await weeklyRes.json();
+      renderWeeklyChart(days);
+    }
   } catch (e) { console.error(e); }
 }
 
@@ -25,7 +45,16 @@ async function loadWeeklyChart() {
     const res = await fetch(API + '/api/stats/daily-income', { headers: headers() });
     if (!res.ok) return;
     const days = await res.json();
+    renderWeeklyChart(days);
+  } catch (e) { console.error(e); }
+}
+
+function renderWeeklyChart(days) {
   const container = document.getElementById('weeklyChartBars');
+  if (!days || days.length === 0) {
+    container.innerHTML = '<div class="ranking-empty">暂无数据</div>';
+    return;
+  }
   const max = Math.max(...days.map(d => d.income), 1);
   container.innerHTML = days.map(d => {
     const pct = Math.max((d.income / max) * 100, 3);
@@ -37,7 +66,6 @@ async function loadWeeklyChart() {
       <span class="weekly-bar-date">${label}</span>
     </div>`;
   }).join('');
-  } catch (e) { console.error(e); }
 }
 
 let currentDailyDate = '';
@@ -232,8 +260,13 @@ async function loadBossRankingPreview() {
     const res = await fetch(API + '/api/stats/boss-ranking/preview?year=' + currentYear + '&month=' + currentMonth, { headers: headers() });
     if (!res.ok) return;
     const rows = await res.json();
+    renderBossRankingPreview(rows);
+  } catch (e) { console.error(e); }
+}
+
+function renderBossRankingPreview(rows) {
   const container = document.getElementById('rankingPreviewList');
-    if (rows.length === 0) {
+  if (!rows || rows.length === 0) {
     container.innerHTML = '<div class="ranking-empty">暂无数据</div>';
     return;
   }
@@ -247,7 +280,6 @@ async function loadBossRankingPreview() {
       <div class="hbar-value">${r.total_income.toFixed(2)}</div>
     </div>`;
   }).join('');
-  } catch (e) { console.error(e); }
 }
 
 let currentBossName = '';
@@ -326,8 +358,13 @@ async function loadPartnerRankingPreview() {
     const res = await fetch(API + '/api/stats/partner-ranking/preview?year=' + currentYear + '&month=' + currentMonth, { headers: headers() });
     if (!res.ok) return;
     const rows = await res.json();
+    renderPartnerRankingPreview(rows);
+  } catch (e) { console.error(e); }
+}
+
+function renderPartnerRankingPreview(rows) {
   const container = document.getElementById('partnerRankingPreviewList');
-    if (rows.length === 0) {
+  if (!rows || rows.length === 0) {
     container.innerHTML = '<div class="ranking-empty">暂无数据</div>';
     return;
   }
@@ -341,7 +378,6 @@ async function loadPartnerRankingPreview() {
       <div class="hbar-value">${r.dispatch_count}单</div>
     </div>`;
   }).join('');
-  } catch (e) { console.error(e); }
 }
 
 function openPartnerRankingPage() {