Add the Next.js web app and shared lesson content.

Move lessons out of the C sources into JSON so the web client can use the same material as the desktop app, and point release builds at desktop/.

Co-authored-by: Cursor <cursoragent@cursor.com>

tools/extract/hardware.mjs

@@ -0,0 +1,73 @@
+import { readFileSync } from 'node:fs';
+import { parseArrayInFunction, trimNulls } from '../lib/cparse.mjs';
+
+/**
+ * Hardware ("Technické vybavení").
+ *
+ * Structurally identical to the network lessons: each `build_hw_unitN_page`
+ * holds a local `NetSlide slides[]` and each `build_hw_unitN_exercise_page`
+ * holds a local `ChoiceQ qs[]` with a parallel `hints[]`.
+ */
+
+const HW_LESSONS = 3;
+
+function toSlide(row, label) {
+  if (!Array.isArray(row)) throw new Error(`${label}: slide is not a braced list`);
+  const [kicker, title, tip, lines] = row;
+  return {
+    kicker: kicker ?? '',
+    title: title ?? '',
+    tip: tip ?? null,
+    lines: trimNulls(lines ?? []).map(String),
+  };
+}
+
+function toChoice(row, hint, label) {
+  if (!Array.isArray(row)) throw new Error(`${label}: question is not a braced list`);
+  const [prompt, options, nOptions, correct] = row;
+  const list = trimNulls(options ?? []).map(String);
+  const n = typeof nOptions === 'number' ? nOptions : list.length;
+
+  if (typeof correct !== 'number' || correct < 0 || correct >= n) {
+    throw new Error(`${label}: correct index ${correct} out of range for ${n} options`);
+  }
+
+  return {
+    kind: 'choice',
+    prompt: String(prompt),
+    options: list.slice(0, n),
+    correct,
+    ...(hint ? { hint: String(hint) } : {}),
+  };
+}
+
+export function extractHardware(desktopDir) {
+  const src = readFileSync(`${desktopDir}/hw.c`, 'utf8');
+  const lessons = [];
+
+  for (let n = 1; n <= HW_LESSONS; n++) {
+    const slides = parseArrayInFunction(src, `build_hw_unit${n}_page`, 'slides')
+      .map((row, i) => toSlide(row, `hw unit ${n} slide ${i + 1}`));
+
+    const exFn = `build_hw_unit${n}_exercise_page`;
+    const qs = parseArrayInFunction(src, exFn, 'qs');
+    const hints = parseArrayInFunction(src, exFn, 'hints');
+
+    lessons.push({
+      id: `unit-${String(n).padStart(2, '0')}`,
+      subject: 'hardware',
+      number: n,
+      titleKey: `hw_unit${n}`,
+      subtitleKey: `hw_unit${n}_sub`,
+      slides,
+      tasks: [{
+        number: 1,
+        title: 'Quiz',
+        subtitleKey: `hw_quiz${n}_head`,
+        items: qs.map((row, i) => toChoice(row, hints[i], `hw unit ${n} q${i + 1}`)),
+      }],
+    });
+  }
+
+  return lessons;
+}