feat(grades): add ranking trend, school-wide summary, score cell, and scope filter

- Add ranking-trend-card and school-wide-summary-card for broader analytics

- Add score-cell and grade-filters components for table rendering

- Add scope-filter and type-guards lib utilities for grade data filtering

- Update actions, data-access (analytics, ranking, main), stats-service, export

- Update schema, types, and grade-utils lib

- Update all grade chart and report components (distribution, trend, comparison, query)

src/modules/grades/components/score-cell.tsx

@@ -0,0 +1,41 @@
+"use client"
+
+import type { JSX } from "react"
+import { cn } from "@/shared/lib/utils"
+
+/**
+ * v4-P1-7: 成绩单元格组件，根据得分率着色。
+ *
+ * 着色规则（对标 PowerSchool / Canvas / 超星学习通）：
+ * - 得分率 < 60%：红色（不及格）
+ * - 得分率 60% ~ 84%：黄色（及格但未达优秀）
+ * - 得分率 ≥ 85%：绿色（优秀）
+ * - fullScore <= 0：不着色（异常数据，避免除零）
+ *
+ * 使用语义化的 Tailwind 类名，避免动态拼接。
+ */
+export function ScoreCell({
+  score,
+  fullScore,
+  className,
+}: {
+  score: number
+  fullScore: number
+  className?: string
+}): JSX.Element {
+  const ratio = fullScore > 0 ? score / fullScore : 1
+  const isFail = ratio < 0.6
+  const isExcellent = ratio >= 0.85
+
+  const colorClass = isFail
+    ? "text-red-600 font-semibold"
+    : isExcellent
+      ? "text-green-600 font-semibold"
+      : "text-yellow-600 font-medium"
+
+  return (
+    <span className={cn("font-mono tabular-nums", colorClass, className)}>
+      {score} / {fullScore}
+    </span>
+  )
+}