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/deutsch-u3.mjs

@@ -0,0 +1,174 @@
+import { readFileSync } from 'node:fs';
+import { parseArray, parseString } from '../lib/cparse.mjs';
+import {
+  alternatives,
+  assemblyItem,
+  assignExercise,
+  ex2Row,
+  ex4Letters,
+  opt,
+  typedItem,
+  u3Fill,
+  u3Letters,
+  vocabSections,
+} from './deutsch-helpers.mjs';
+
+/**
+ * Deutsch Unit 3 ("Bei uns zu Hause").
+ *
+ * Most tasks go through `u3_build_drop` (dropdown gaps over a shared pool);
+ * the rest are hand-built pages whose data arrays are read here directly.
+ */
+export function extractDeutschUnit3(desktopDir) {
+  const src = readFileSync(`${desktopDir}/exercise_u3.c`, 'utf8');
+  const tasks = [];
+
+  /** `u3_build_drop`: `U3Fill` rows sharing one dropdown pool. */
+  const dropTask = (number, title, subtitleKey, prefix, { example, gloss } = {}) => {
+    const glosses = gloss ? parseArray(src, `${prefix}_gloss`) : null;
+    return {
+      number,
+      title,
+      subtitleKey,
+      ...(example ? { example } : {}),
+      pool: parseArray(src, `${prefix}_pool`).map(String),
+      items: parseArray(src, `${prefix}_rows`).map((row, i) =>
+        u3Fill(row, { gloss: glosses ? opt(glosses[i]) : undefined })),
+    };
+  };
+
+  tasks.push(dropTask(1, 'Familienpaare', 'sub3_pair', 'ex1_u3', {
+    example: 'Beispiel: der Vater ↔ die Mutter',
+  }));
+
+  /* 2 — mein oder dein: rows grouped per item, each item has one translation. */
+  tasks.push({
+    number: 2,
+    title: 'mein oder dein',
+    subtitleKey: 'sub3_poss',
+    example:
+      'Beispiel: Ist das dein Vater? – Nein, das ist nicht mein Vater. ' +
+      'Das ist sein Onkel.',
+    pool: parseArray(src, 'ex2_u3_pool').map(String),
+    items: parseArray(src, 'ex2_u3_items').flatMap(([czech, rowsRef]) => {
+      const name = rowsRef?.__c;
+      if (!name) throw new Error(`ex2_u3_items row group for '${czech}' has no data array`);
+      return parseArray(src, name).map((row) => ex2Row(row, czech));
+    }),
+  });
+
+  tasks.push(dropTask(3, 'ein / kein', 'sub3_haustier', 'ex3_u3', {
+    example:
+      'Beispiel: Hast du eine Katze? – Nein, ich habe keine Katze. ' +
+      'Ich habe einen Hund.',
+  }));
+
+  /* 4 — Lückentext: missing letters inside words. */
+  tasks.push({
+    number: 4,
+    title: 'Lückentext',
+    subtitleKey: 'sub3_buchst',
+    items: parseArray(src, 'ex4_u3_rows').map(ex4Letters),
+  });
+
+  /* 5 — Marcos Familie */
+  tasks.push({
+    number: 5,
+    title: 'Marcos Familie',
+    subtitleKey: 'sub3_marco',
+    note: parseString(src, 'ex5_u3_bank'),
+    items: parseArray(src, 'ex5_u3_rows').map(typedItem),
+  });
+
+  /* 6 — Sortieren */
+  tasks.push({
+    number: 6,
+    title: 'Sortieren',
+    subtitleKey: 'sub3_sort',
+    items: [assignExercise(src, 'ex6_u3_items', 'ex6_u3_groups', 'ex6_u3_meaning')],
+  });
+
+  /* 7 — Possessivtabelle: nouns down the side, persons across the top. */
+  {
+    const persons = ['ich', 'du', 'er', 'sie', 'es', 'wir', 'ihr', 'sie / Sie'];
+    const nouns = ['der Garten', 'die Idee', 'das Fest', 'die Geschwister'];
+    const forms = [
+      ['mein', 'dein', 'sein', 'ihr', 'sein', 'unser', 'euer', 'ihr'],
+      ['meine', 'deine', 'seine', 'ihre', 'seine', 'unsere', 'eure', 'ihre'],
+      ['mein', 'dein', 'sein', 'ihr', 'sein', 'unser', 'euer', 'ihr'],
+      ['meine', 'deine', 'seine', 'ihre', 'seine', 'unsere', 'eure', 'ihre'],
+    ];
+
+    tasks.push({
+      number: 7,
+      title: 'Possessivtabelle',
+      subtitleKey: 'sub3_tabelle',
+      items: [{
+        kind: 'table',
+        columns: persons,
+        rows: nouns,
+        answers: forms.map((row) => row.map((value) => ({ value }))),
+      }],
+    });
+  }
+
+  tasks.push(dropTask(8, 'Akkusativ', 'sub3_akk', 'ex8_u3', {
+    example: 'Beispiel: die Inliner (ich) → Ich brauche meine Inliner.',
+    gloss: true,
+  }));
+  tasks.push(dropTask(9, 'kein / nicht', 'sub3_nicht', 'ex9_u3'));
+
+  /* 10 — Sätze bauen */
+  {
+    const meanings = parseArray(src, 'ex10_u3_meaning');
+    tasks.push({
+      number: 10,
+      title: 'Sätze bauen',
+      subtitleKey: 'sub3_satz',
+      items: parseArray(src, 'ex10_u3_items').map((row, i) => assemblyItem(row, meanings[i])),
+    });
+  }
+
+  /* 11 + 14 — `u3_build_kw`: free sentence checked for the required keywords. */
+  const keywordTask = (number, title, subtitleKey, qsName, example) => ({
+    number,
+    title,
+    subtitleKey,
+    example,
+    items: parseArray(src, qsName).map(([prompt, answers, mean, german]) => ({
+      kind: 'typed',
+      prompt: String(prompt),
+      answers: alternatives(answers),
+      substring: true,
+      ...(opt(mean) ? { meaning: String(mean) } : {}),
+      ...(opt(german) ? { model: String(german) } : {}),
+    })),
+  });
+
+  tasks.push(keywordTask(11, 'Was siehst du?', 'sub3_sehen', 'ex11_u3_qs',
+    'Beispiel: Ich sehe eine Burg. / Ich sehe ein Schloss.'));
+
+  tasks.push(dropTask(12, 'Wem gehört das?', 'sub3_wem', 'ex12_u3'));
+  tasks.push(dropTask(13, 'Es gibt …', 'sub3_gibt', 'ex13_u3'));
+
+  tasks.push(keywordTask(14, 'Beschreiben', 'sub3_saetze', 'ex14_u3_qs',
+    'Beispiel: Ich sehe einen Jungen. Er liest ein Buch.'));
+
+  /* 15 — Wochenende: missing letters again, but with no per-gap glosses. */
+  tasks.push({
+    number: 15,
+    title: 'Wochenende',
+    subtitleKey: 'sub3_wochen',
+    items: parseArray(src, 'ex15_u3_rows').map(u3Letters),
+  });
+
+  return {
+    id: 'unit-03',
+    subject: 'deutsch',
+    number: 3,
+    title: { cs: 'Bei uns zu Hause', en: 'Bei uns zu Hause' },
+    slides: [],
+    tasks,
+    vocab: vocabSections(src, 'u3_trans_sections'),
+  };
+}