Math tracker (/trackers/math): Evan Chen's Napkin, chapter by chapter

Schema math (parts, chapters, sections, activity), seeded with all 100 chapters
(Ch 0-94, appendix A-E), 647 sections, PDF pages, exercise counts and approximate
prereqs. Triggers stamp started_at/completed_at and log status/exercise/note/section
changes; math.apply_progress(jsonb) applies the JSON format bots send. Private by
default via MATH_PRIVATE in #lib/math (owner-only prefix + lock in every tracker list).
Overall + per-part progress, current chapter, prereq hints, quick status buttons,
exercises stepper, notes, optional section ticks, activity log, dependency chart.
Deploy preflight checks the math schema (4 tables, 100 chapters).

src/routes/trackers/math/+page.server.ts

@@ -0,0 +1,33 @@
+import { MATH_PRIVATE } from '#lib/math.js';
+import { applyFromForm, loadMath } from '#lib/server/math.js';
+import { isOwner, requireOwner } from '#lib/server/owner.js';
+import { fail } from '@sveltejs/kit';
+import type { Actions, PageServerLoad } from './$types';
+
+// Math tracker: Evan Chen's "An Infinitely Large Napkin". Private by default (MATH_PRIVATE in
+// #lib/math): then everyone else gets a 404 for the page and its __data.json, and
+// hooks.server.ts 404s the path as a backstop. Edits are always owner-only.
+export const load: PageServerLoad = async (event) => {
+	if (MATH_PRIVATE) requireOwner(event);
+	const owner = isOwner(event);
+	if (owner) event.setHeaders({ 'cache-control': 'private, no-store' });
+	return {
+		owner,
+		private: MATH_PRIVATE,
+		now: Date.now(),
+		...(await loadMath(owner)),
+		seo: {
+			title: 'Math tracker',
+			description: "Working through Evan Chen's An Infinitely Large Napkin, chapter by chapter.",
+			index: !MATH_PRIVATE
+		}
+	};
+};
+
+export const actions: Actions = {
+	progress: async (event) => {
+		requireOwner(event);
+		const r = await applyFromForm(await event.request.formData());
+		return r.ok ? { ok: true } : fail(400, { message: r.message });
+	}
+};