Read the quizzes behind H5P elements

A quiz in Schulcloud is an H5P element, and a board hands over nothing but a
contentId — so a teacher's exercise was until now a line saying one exists.
The player shows a single question at a time, which makes it look like
something to step through or scrape. It is not:
`GET /api/v3/h5p-editor/params/{contentId}` returns the JSON the player is fed,
so one request holds every question, every option and which of them are
correct. (`play/{id}` is the same content plus the player's script lists: 74 kB
against 51 kB for the live quiz. Neither docs-json describes the service.)

get_h5p prints the exercise, and solutions=false keeps the options while
dropping the answers, so it can be used to ask the questions instead of
answering them. get_board names the exercise — title, question count, kinds —
rather than printing a bare id, and the crawl indexes its text, so a phrase
that exists only inside a quiz is now findable. That is the treatment pads
already get, for the same reason: it is course material and nothing else
surfaces it.

What varies is the shape inside `params`, which belongs to whichever H5P
library the teacher used. Modelled: MultiChoice, whose `behaviour.singleAnswer`
is the only honest source for "tick exactly one"; TrueFalse, whose `correct` is
the string "true"; the cloze libraries, which mark solutions inline as
`*answer:tip*`; SingleChoiceSet and Summary, which put the correct option first
and let the player shuffle; and Column. Anything else has its text harvested
and labelled unmodelled — an exercise reported as "0 questions" would be worse
than a clumsy rendering of one. The harvest skips the UI and l10n subtrees, or
a quiz reads as "Überprüfen, Wiederholen, Absenden".

Verified against this account's quiz, an H5P.QuestionSet of 20 MultiChoice
questions on a room's board: 239 tests, smoke 91/91 live-only and 93/93 with
the index.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/smoke.mjs

@@ -292,6 +292,9 @@ console.log('\n== file manager (Dateien) ==');
 }
 
 console.log('\n== rooms ==');
+// Collected here and used by the H5P section below: a room's boards are where
+// this account's quiz lives.
+const roomBoardIds = [];
 // Rooms ("Räume") are a separate space from courses. An account in none is
 // normal — and is exactly the state that hid this whole feature — so the check
 // is that the tools answer sensibly either way, not that rooms exist.
@@ -302,6 +305,7 @@ console.log('\n== rooms ==');
 	if (roomId) {
 		const room = await call('get_room', { roomId });
 		check('get_room opens a room', !room.isError && /Room id:/.test(room.text), roomId);
+		roomBoardIds.push(...[...room.text.matchAll(/\(`([0-9a-f]{24})`\)/g)].map((m) => m[1]).slice(0, 8));
 		const roomBoardId = room.text.match(/### Boards[\s\S]*?\(`([0-9a-f]{24})`\)/)?.[1];
 		if (roomBoardId) {
 			const board = await call('get_board', { boardId: roomBoardId });
@@ -314,6 +318,47 @@ console.log('\n== rooms ==');
 	}
 }
 
+console.log('\n== H5P exercises ==');
+// A quiz is an H5P element on a board, and Schulcloud has nothing else like it.
+// Which boards hold one is data, so the id is discovered by scanning the boards
+// this account can see — course boards first, then the rooms', which is where
+// this account's quiz actually lives.
+{
+	let contentId;
+	let foundOn;
+	const boardsToScan = [...boardIds, ...roomBoardIds];
+	for (const boardId of boardsToScan) {
+		const board = await call('get_board', { boardId, includeFiles: false });
+		const match = board.text.match(/content `([0-9a-f]{24})` — all of it with get_h5p/);
+		if (match) {
+			contentId = match[1];
+			foundOn = boardId;
+			break;
+		}
+	}
+	if (contentId) {
+		check('get_board names an H5P exercise and its question count', true, `board ${foundOn}, content ${contentId}`);
+
+		const full = await call('get_h5p', { contentId });
+		check(
+			'get_h5p returns every question at once, with the solutions marked',
+			!full.isError && /^### 1\. /m.test(full.text) && /✔/.test(full.text),
+			full.text.split('\n')[0],
+		);
+
+		const withheld = await call('get_h5p', { contentId, solutions: false });
+		check(
+			'solutions=false keeps the options and drops the answers',
+			!withheld.isError && /^### 1\. /m.test(withheld.text) && !/✔/.test(withheld.text) && /Solutions withheld/.test(withheld.text),
+			withheld.text.split('\n')[0],
+		);
+	} else {
+		check('get_board names an H5P exercise and its question count', true, 'no board here holds one');
+	}
+	const missing = await call('get_h5p', { contentId: '000000000000000000000000' });
+	check('an unknown content id is a tool error naming the id', missing.isError && /404/.test(missing.text), missing.text.split('\n')[0]);
+}
+
 console.log('\n== resources and prompts ==');
 // Courses and rooms are resources a person attaches; the prompts are German
 // requests picked from a menu. Both reuse the tools' reads, so what is checked