Add questions anywhere with a grouped type picker

[PhilReinking]

"Add question" now opens a picker with the answer types grouped as Text, Choice, Rating, Other and Content. The new question opens where you asked for it, with the cursor in its text. Fixes BITS-283.

• Add between questions ("+ Add question here" on hover or focus), with the gutter + or with "Add question below" in a question's menu.
• "Add question" at the end of the document adds at the end.
• "/" in an empty question changes that question's type.
• The picker scrolls into view. On a phone the keyboard stays down until you tap the search.
• Touch screens don't show the line or the gutter +.

Heads-up: the answer types have new names in the editor and the docs: Multiple Choice is now Single choice, Short Answer is Short text, No Input is Text only, Secret is Hidden text. Docs links stay the same.

Tested: Vitest (new tests fail without the change), lint, vue-tsc, build. By hand at 1440 and 390 on my own server.

Not tested: real touch devices. Stacked on #275, so CI runs once this targets main.

🤖 Generated with Claude Code

[PhilReinking]

OK at e710ffd. No CI (stacked): Vitest 312, lint, vue-tsc and the build pass locally. 9 new tests fail on 711992e.

Should: when a new question opens under the mouse, a toolbar tooltip takes the focus, so the cursor isn't in its text. #275's tooltip fix in app.ts solves it; with the mouse away, the cursor lands in the text. Creates send the picked type, and into an empty group the group as scope.

[PhilReinking]

Nit: "/" doesn't add a question, it picks the type of the empty one.

Suggested change

	- Add a question right where you need it: between questions, from a question's menu or with "/" in an empty question. A picker groups the answer types as Text, Choice, Rating, Other and Content, and the new question opens ready to type. The answer types have new names, like Single choice, Short text and Text only. (#276)
	- Add a question right where you need it: between questions or from a question's menu, and type "/" in an empty question to pick its answer type. A picker groups the answer types as Text, Choice, Rating, Other and Content, and the new question opens ready to type. The answer types have new names, like Single choice, Short text and Text only. (#276)

[PhilReinking]

OK at 17d4bd1. No CI (stacked), local runs: Vitest 367, lint, vue-tsc, build and the docs build pass. On the merged head, Alt+Up/Down moves keep the right order after reload (4 of 4), the picker creates with the right type, place and group, and the end button adds at the end, also after reload. A new question that opens under the mouse keeps the cursor in its text.

[PhilReinking]

Should: with this picker open, a click on the end "Add question" opens the end picker, but the cursor comes back into this text a frame later (tiptap focuses on the next animation frame). Typing then goes into the question text and saves it. Maybe refocus only after Esc or a pick, not after a click outside. Not run.

[PhilReinking]

OK at 17d3ccc. No CI (stacked), local runs: Vitest 368, lint, vue-tsc, build and the docs build pass. The new QuestionCard test fails on 17d4bd1. In the browser, a click on the end "Add question" while the "/" picker is open now leaves the cursor in the end picker's search, and Esc or a pick still give it back to the text.

[PhilReinking]

Should: the other pickers have the same slip. With the end picker open, a click into the open question's text puts the cursor back on "Add question", so typing goes nowhere. TypePicker already sends false here. Tested: Vitest, lint, vue-tsc, and in the browser the click keeps the cursor in the text while Esc still returns to the button.

Suggested change

	export function closePicker() {
	const spot = addAt.value;
	addAt.value = null;
	if (opener?.isConnected) {
	opener.focus();
	} else if (spot) {
	focusBlock(spot.after);
	}
	}
	export function closePicker(returnFocus = true) {
	const spot = addAt.value;
	addAt.value = null;
	// a click elsewhere leaves the focus where the click put it
	if (!returnFocus) {
	return;
	}
	if (opener?.isConnected) {
	opener.focus();
	} else if (spot) {
	focusBlock(spot.after);
	}
	}

[PhilReinking]

OK at e323b14. No CI (stacked), local runs: Vitest 369, lint, vue-tsc and the build pass. The new FormDocument test fails on 17d3ccc. In the browser, a click into the open question's text with the end picker open keeps the cursor there, and Esc still returns it to Add question.

[PhilReinking]

Landed in main with #282 (the editor rebuild as one PR); this PR's commits are part of it.