Add printable report cards, progress reports and invoices

Three documents, all print-styled rather than generated server-side: no
PDF dependency is added, and "Save as PDF" in the browser produces the
file. @media print in styles.css strips the app chrome (.no-print) and
breaks each student onto its own sheet (.print-page).

- Report card: weighted category breakdown, overall percent and letter
  from the existing gradebook config, plus an attendance summary.
- Academic progress report: the same, plus assignment-level detail —
  a mid-term report is only actionable with the underlying work listed.
- 504 / IEP progress report: each goal's baseline, target, status and
  progress entries within the period, for the quarterly report IDEA
  requires. RLS keeps it to the case manager, admins and parents.
- Invoice, reachable per student from the tuition ledger: opening
  balance carried forward, itemised activity, and balance due.

Grade maths is reused from lib/grades and the class grading config from
useEffectiveConfig, so report cards cannot drift from the gradebook.

The "Email to parents" button opens a prefilled mailto: draft — the same
mechanism the intake-link share already uses. It gathers addresses from
intake guardians and linked parent accounts. mailto cannot attach a file,
so the itemisation goes in the body as text; sending a real attachment
would need a transactional email provider and an API key.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/lib/reports.ts

@@ -0,0 +1,66 @@
+// Shared helpers for the printable documents: report cards, progress reports,
+// and tuition invoices.
+import { todayISO } from "@/lib/plans";
+
+export const SCHOOL_NAME = "Bayside Academy";
+
+export const money = (cents: number) =>
+  `${cents < 0 ? "-" : ""}$${(Math.abs(cents) / 100).toFixed(2)}`;
+
+export type AttendanceRow = { status: string; date: string };
+
+export type AttendanceCounts = {
+  present: number;
+  late: number;
+  absent: number;
+  excused: number;
+  recorded: number;
+  /** Share of recorded days the student actually attended (present or late). */
+  attendedPct: number | null;
+};
+
+export function summarizeAttendance(
+  rows: AttendanceRow[],
+  from: string,
+  to: string,
+): AttendanceCounts {
+  const inRange = rows.filter((r) => r.date >= from && r.date <= to);
+  const count = (s: string) => inRange.filter((r) => r.status === s).length;
+  const present = count("present");
+  const late = count("late");
+  const absent = count("absent");
+  const excused = count("excused");
+  const recorded = inRange.length;
+  return {
+    present,
+    late,
+    absent,
+    excused,
+    recorded,
+    attendedPct: recorded === 0 ? null : ((present + late) / recorded) * 100,
+  };
+}
+
+// School year runs Aug 1 → Jul 31, so a report pulled in e.g. February still
+// covers the year that began the previous August.
+export function schoolYearRange(today = new Date()): { from: string; to: string } {
+  const startYear = today.getMonth() >= 7 ? today.getFullYear() : today.getFullYear() - 1;
+  return { from: `${startYear}-08-01`, to: `${startYear + 1}-07-31` };
+}
+
+export function monthToDateRange(today = new Date()): { from: string; to: string } {
+  const y = today.getFullYear();
+  const m = String(today.getMonth() + 1).padStart(2, "0");
+  return { from: `${y}-${m}-01`, to: todayISO() };
+}
+
+export const REPORT_TYPES = [
+  { value: "report_card", label: "Report card" },
+  { value: "progress", label: "Academic progress report" },
+  { value: "iep", label: "504 / IEP progress report" },
+] as const;
+
+export type ReportType = (typeof REPORT_TYPES)[number]["value"];
+
+export const reportTitle = (t: ReportType) =>
+  REPORT_TYPES.find((r) => r.value === t)?.label ?? "Report";