fix(i18n): select the plural form by category, and unbreak the tests typecheck

Two findings from review on #451.

`fitClip.test.ts` kept an `AspectRatio` import after the fixtures that used it
were deleted, and the Typecheck (tests) job failed on it. I did not catch that
because I ran `tsc --noEmit` all along and read it as full coverage: tsconfig.json
excludes `**/*.test.ts`, and the test files go through tsconfig.test.json in a
separate CI job — a gate its own comment says to keep at zero. So none of the
test files added on this branch had ever been typechecked locally. Both configs
from here.

Plural selection now reads the CLDR category instead of collapsing everything
that is not `one`. Russian has four, and 2-4 takes "клипа", so the menu rendered
"2 клипов" — wrong, not merely coarse. `few` is authored per locale and falls
back to `many`, so adding a form stays a catalog change.

Every locale gets the key rather than only Russian, because the loader falls back
to English for a missing one and Arabic selects `few` too. The strings other
locales get are the ones they were already using for that category, not new
grammar. Arabic's `two` and `many` are still wrong — it has six categories, and
I could not verify the grammar, so it stays on the fallback instead of being
filled in with a guess. That wants a native speaker.

Refs #84
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: EtienneLescot

src/components/ai-edition/RightPanes.tsx

@@ -1484,17 +1484,24 @@ export function fitClipPatch(nativeToken: AspectRatio): EditorSettingsPatch {
 }
 
 /**
- * "1 clip" / "2 clips", picked through Intl.PluralRules rather than `count === 1`.
+ * The catalog key for a count, by CLDR plural category.
  *
- * The catalog has no plural machinery — `translate` interpolates and nothing else — so the two
- * forms are two keys. Choosing between them by CLDR category instead of by equality is what
- * makes French say "0 clip" and not "0 clips", and it degrades honestly for the locales whose
- * rules need more than two forms rather than pretending English's rules are universal.
+ * `translate` interpolates and nothing else, so each form is its own key. Selecting by
+ * category rather than by `count === 1` is what makes French say "0 clip" — and, more to the
+ * point, what lets a locale carry more than two forms at all: Russian needs "клипа" for 2–4
+ * and "клипов" for 5+, so mapping everything that is not `one` onto a single plural produced
+ * "2 клипов", which is simply wrong rather than merely coarse.
+ *
+ * Falls back to `fitClipMany` for any category a locale has not authored, so adding a form is
+ * a catalog change and never a code change. Arabic still needs its `two`, `few` and `many`
+ * forms — it has six categories and I could not verify the grammar, so it is deliberately
+ * left on the fallback rather than filled in with a guess.
  */
-function pluralKey(locale: string, count: number): "effects.fitClipOne" | "effects.fitClipMany" {
-	return new Intl.PluralRules(locale).select(count) === "one"
+function pluralKey(locale: string, count: number): string {
+	const category = new Intl.PluralRules(locale).select(count);
+	return category === "one"
 		? "effects.fitClipOne"
-		: "effects.fitClipMany";
+		: `effects.fitClip${category === "few" ? "Few" : "Many"}`;
 }
 
 // ─── Video Effects ─────────────────────────────────────────────────

src/components/ai-edition/fitClip.test.ts

@@ -4,7 +4,6 @@
 // unfixable to someone who already found the padding slider — so it gets pinned here.
 
 import { describe, expect, it } from "vitest";
-import type { AspectRatio } from "@/utils/aspectRatioUtils";
 import { fitClipPatch } from "./RightPanes";
 
 describe("fitClipPatch", () => {

src/components/ai-edition/fitClipShapes.test.tsx

@@ -8,6 +8,7 @@ import "@testing-library/jest-dom";
 import { cleanup, fireEvent, render, screen, waitFor, within } from "@testing-library/react";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { I18nProvider } from "@/contexts/I18nContext";
+import { LOCALE_STORAGE_KEY } from "@/i18n/config";
 import type { AxcutDocument } from "@/lib/ai-edition/schema";
 import { createEmptyDocument } from "@/lib/ai-edition/schema";
 import { useProjectStore } from "@/lib/ai-edition/store/projectStore";
@@ -56,7 +57,8 @@ function documentWithShapes(shapes: Array<[number, number]>): AxcutDocument {
 	} as unknown as AxcutDocument;
 }
 
-function mount(doc: AxcutDocument) {
+function mount(doc: AxcutDocument, locale?: string) {
+	if (locale) localStorage.setItem(LOCALE_STORAGE_KEY, locale);
 	useProjectStore.setState({ document: doc });
 	return render(
 		<I18nProvider>
@@ -79,9 +81,13 @@ function frameSettings() {
 }
 
 beforeEach(() => {
+	localStorage.clear();
 	useProjectStore.setState({ document: null });
 });
-afterEach(cleanup);
+afterEach(() => {
+	cleanup();
+	localStorage.clear();
+});
 
 describe("fitting a clip is an action, and a choice only when there is one", () => {
 	it("acts without asking when the timeline holds one shape", async () => {
@@ -174,6 +180,29 @@ describe("fitting a clip is an action, and a choice only when there is one", ()
 		).toBeInTheDocument();
 	});
 
+	it("counts in Russian with the form the count actually needs", () => {
+		// Russian has four plural categories, and 2-4 takes "клипа". Mapping everything that
+		// is not `one` onto a single plural rendered "2 клипов", which is wrong rather than
+		// merely coarse — the reason the count goes through Intl.PluralRules and not
+		// `count === 1`.
+		mount(
+			documentWithShapes([
+				[1920, 1080],
+				[1920, 1080],
+				[1080, 1920],
+			]),
+			"ru",
+		);
+		fireEvent.click(screen.getByRole("button", { name: "Подогнать" }));
+		const menu = screen.getByRole("menu");
+		expect(
+			within(menu).getByRole("menuitem", { name: /1920 × 1080.*2 клипа/ }),
+		).toBeInTheDocument();
+		expect(
+			within(menu).getByRole("menuitem", { name: /1080 × 1920.*1 клип$/ }),
+		).toBeInTheDocument();
+	});
+
 	it("collapses same-shape clips to one entry, labelled with the biggest", () => {
 		mount(
 			documentWithShapes([

src/i18n/locales/ar/settings.json

@@ -79,6 +79,7 @@
 		"formatOriginal": "الأصلي",
 		"fitClip": "ملاءمة",
 		"fitClipOne": "مقطع واحد",
+		"fitClipFew": "{{count}} مقاطع",
 		"fitClipMany": "{{count}} مقاطع",
 		"motion": "الحركة",
 		"help": "تنسيق إطار التسجيل: ضبابية الخلفية، والظل، وضبابية الحركة، واستدارة الزوايا، والحشو حول الفيديو."

src/i18n/locales/en/settings.json

@@ -85,6 +85,7 @@
 		"formatOriginal": "Original",
 		"fitClip": "Fit",
 		"fitClipOne": "{{count}} clip",
+		"fitClipFew": "{{count}} clips",
 		"fitClipMany": "{{count}} clips",
 		"motion": "Motion",
 		"help": "Frame styling for the recording: background blur, drop shadow, motion blur, corner radius, and padding around the video."

src/i18n/locales/es/settings.json

@@ -78,6 +78,7 @@
 		"formatOriginal": "Original",
 		"fitClip": "Ajustar",
 		"fitClipOne": "{{count}} clip",
+		"fitClipFew": "{{count}} clips",
 		"fitClipMany": "{{count}} clips",
 		"motion": "Movimiento",
 		"on": "activado",

src/i18n/locales/fr/settings.json

@@ -78,6 +78,7 @@
 		"formatOriginal": "Original",
 		"fitClip": "Ajuster",
 		"fitClipOne": "{{count}} clip",
+		"fitClipFew": "{{count}} clips",
 		"fitClipMany": "{{count}} clips",
 		"motion": "Mouvement",
 		"on": "activé",

src/i18n/locales/it/settings.json

@@ -79,6 +79,7 @@
 		"formatOriginal": "Originale",
 		"fitClip": "Adatta",
 		"fitClipOne": "{{count}} clip",
+		"fitClipFew": "{{count}} clip",
 		"fitClipMany": "{{count}} clip",
 		"motion": "Movimento",
 		"help": "Stile della cornice della registrazione: sfocatura dello sfondo, ombra, sfocatura di movimento, raggio degli angoli e margine attorno al video."

src/i18n/locales/ja-JP/settings.json

@@ -78,6 +78,7 @@
 		"formatOriginal": "元のサイズ",
 		"fitClip": "合わせる",
 		"fitClipOne": "{{count}} クリップ",
+		"fitClipFew": "{{count}} クリップ",
 		"fitClipMany": "{{count}} クリップ",
 		"motion": "モーション",
 		"on": "オン",

src/i18n/locales/ko-KR/settings.json

@@ -79,6 +79,7 @@
 		"formatOriginal": "원본",
 		"fitClip": "맞추기",
 		"fitClipOne": "{{count}}개 클립",
+		"fitClipFew": "{{count}}개 클립",
 		"fitClipMany": "{{count}}개 클립",
 		"motion": "모션",
 		"help": "녹화 프레임 스타일: 배경 흐림, 그림자, 모션 블러, 모서리 둥글기, 영상 주변 여백."