fix: 修复统计图表不显示与对比上月Infinity问题

- ChartWrapper: 添加 type 属性修复 uCharts 不渲染
- ChartWrapper: 使用 pixelRatio=1 避免双重缩放导致字体线条过大
- ChartWrapper: 统一 fontSize/fontColor/padding 配置
- ChartWrapper: 挂载时保存实例引用避免异步回调中 getCurrentInstance 返回 undefined
- stats: Number() 强制类型转换避免字符串导致 Infinity
- stats: !prev 宽松判断覆盖 null/undefined/0 除零情况
- stores: fetchOverview/fetchCategoryStats/fetchTrend 确保数据字段为数字

client/src/components/ChartWrapper/ChartWrapper.vue

@@ -1,6 +1,7 @@
 <template>
   <view class="chart-wrap">
     <canvas
+      type="2d"
       :canvas-id="canvasId"
       :id="canvasId"
       class="chart-canvas"
@@ -25,6 +26,8 @@ const props = withDefaults(defineProps<{
 
 const emit = defineEmits(['tap'])
 
+// 挂载时保存实例引用，避免异步回调中 getCurrentInstance 返回 undefined
+const instance = getCurrentInstance()
 let chartInstance: any = null
 
 function drawChart() {
@@ -39,6 +42,43 @@ function drawChart() {
   // #endif
 }
 
+function buildConfig(ctx: any, canvas2d: boolean, cssWidth: number, cssHeight: number) {
+  // canvas 已通过 ctx.scale(dpr) 处理缩放，uCharts 用 pixelRatio=1 避免双重缩放
+  const base: any = {
+    type: props.type,
+    context: ctx,
+    canvas2d,
+    pixelRatio: 1,
+    width: cssWidth,
+    height: cssHeight,
+    animation: true,
+    background: '#FFFFFF',
+    padding: [20, 20, 20, 20],
+    fontSize: 10,
+    fontColor: '#8B7E7E',
+    title: { show: false },
+    subtitle: { show: false },
+    legend: { show: false },
+    dataLabel: false,
+    enableScroll: false,
+    ...props.chartData
+  }
+
+  // 饼图开启数据标签
+  if (props.type === 'pie') {
+    base.dataLabel = true
+    base.padding = [30, 30, 30, 30]
+  }
+
+  // 折线图/柱状图坐标轴字体
+  if (props.type === 'line' || props.type === 'column') {
+    base.xAxis = { fontSize: 10, ...base.xAxis }
+    base.yAxis = { fontSize: 10, ...base.yAxis }
+  }
+
+  return base
+}
+
 function drawChartH5() {
   try {
     const canvas = document.querySelector(`#${props.canvasId}`) as HTMLCanvasElement
@@ -53,19 +93,7 @@ function drawChartH5() {
     canvas.height = rect.height * dpr
     ctx.scale(dpr, dpr)
 
-    const config: any = {
-      context: ctx,
-      canvas2d: true,
-      pixelRatio: dpr,
-      width: rect.width,
-      height: rect.height,
-      animation: true,
-      background: '#FFFFFF',
-      padding: [15, 15, 15, 15],
-      ...props.chartData
-    }
-
-    chartInstance = new uCharts(config)
+    chartInstance = new uCharts(buildConfig(ctx, true, rect.width, rect.height))
   } catch (e) {
     console.error('[Chart] H5 draw error:', e)
   }
@@ -73,11 +101,18 @@ function drawChartH5() {
 
 function drawChartMP() {
   try {
-    const query = uni.createSelectorQuery().in(getCurrentInstance()?.proxy)
+    if (!instance?.proxy) return
+
+    const query = uni.createSelectorQuery().in(instance.proxy)
     query.select(`#${props.canvasId}`)
+      // @ts-ignore
       .fields({ node: true, size: true })
-      .exec((res) => {
-        if (!res || !res[0]) return
+      .exec((res: any) => {
+        if (!res || !res[0] || !res[0].node) {
+          console.warn('[Chart] Canvas node not found, fallback to old API')
+          drawChartMPLegacy()
+          return
+        }
 
         const canvas = res[0].node
         const ctx = canvas.getContext('2d')
@@ -87,22 +122,29 @@ function drawChartMP() {
         canvas.height = res[0].height * dpr
         ctx.scale(dpr, dpr)
 
-        const config: any = {
-          context: ctx,
-          canvas2d: true,
-          pixelRatio: dpr,
-          width: res[0].width,
-          height: res[0].height,
-          animation: true,
-          background: '#FFFFFF',
-          padding: [15, 15, 15, 15],
-          ...props.chartData
-        }
-
-        chartInstance = new uCharts(config)
+        chartInstance = new uCharts(buildConfig(ctx, true, res[0].width, res[0].height))
       })
   } catch (e) {
     console.error('[Chart] MP draw error:', e)
+    drawChartMPLegacy()
+  }
+}
+
+// 兼容旧版小程序 canvas API
+function drawChartMPLegacy() {
+  try {
+    const ctx = uni.createCanvasContext(props.canvasId, instance?.proxy)
+    if (!ctx) return
+
+    const query = uni.createSelectorQuery().in(instance?.proxy)
+    query.select(`#${props.canvasId}`)
+      .boundingClientRect((rect: any) => {
+        if (!rect) return
+        chartInstance = new uCharts(buildConfig(ctx, false, rect.width, rect.height))
+      })
+      .exec()
+  } catch (e) {
+    console.error('[Chart] MP legacy draw error:', e)
   }
 }