fix(clip): a clip refusal speaks the user's language, and a choice in the clip form no longer sends it

The backend refuses a clip with a structured reason, but the client showed every one as the generic
"couldn't make the clip": each reason now has its own message in both languages, held to the
backend's reasons in both directions by the contract test. A segmented toggle's and the priority
stepper's buttons had no type, so inside a form one of them submitted it.

frontend/src/components/ui/PriorityStepper.tsx

@@ -36,6 +36,7 @@ function PriorityStepButton({
 }) {
   return (
     <button
+      type="button"
       onPointerDown={(e) => {
         // Keep receiving pointer events even if the pointer drifts off the small button mid-hold.
         try {
@@ -162,6 +163,7 @@ export function PriorityStepper({
           } ${cls.value}`}
         >
           <button
+            type="button"
             ref={editTarget}
             onClick={beginEdit}
             aria-label={t("common.priority.edit")}

frontend/src/components/ui/SegmentedToggle.tsx

@@ -62,6 +62,8 @@ export default function SegmentedToggle<T extends string>({
       {options.map((o) => (
         <button
           key={o.value}
+          // A choice, never a submit: inside a form (the clip panel) a bare button would send it.
+          type="button"
           onClick={() => onChange(o.value)}
           title={o.title}
           aria-pressed={value === o.value}

frontend/src/i18n/backendIds.contract.test.ts

@@ -170,6 +170,12 @@ const youtubeReasons = [
     backend("youtube/client.py").match(/^YouTubeRefusal = Literal\[([^\]]*)\]/m)?.[1] ?? ""
   ).matchAll(/"(\w+)"/g),
 ].map((m) => m[1]!);
+// A clip the server will not cut → `clip.errors.<reason>`: every `ClipError("<reason>")` in the backend.
+const clipReasons = [
+  ...new Set(
+    appSources().flatMap((src) => [...src.matchAll(/ClipError\("(\w+)"\)/g)].map((m) => m[1]!)),
+  ),
+];
 
 // The closed English vocabularies the backend WRITES into data, named through `vocab.<group>`
 // (lib/vocab) by their letters-and-digits key. A word the backend adds shows in English until named —
@@ -233,6 +239,7 @@ describe("backend ids have their names in both languages", () => {
     expect(goneWhats).toEqual(expect.arrayContaining(["playlist", "download", "job"]));
     expect(opaqueWhats).toEqual([]);
     expect(youtubeReasons).toEqual(["quota", "reconnect", "unavailable", "gone"]);
+    expect(clipReasons).toEqual(expect.arrayContaining(["too_long", "past_end"]));
     expect(crewJobs).toEqual(
       expect.arrayContaining(["Director", "Creator", "Director of Photography"]),
     );
@@ -336,6 +343,13 @@ describe("backend ids have their names in both languages", () => {
       ).toEqual([]);
     });
 
+    it(`${lang}: every reason a clip is refused, and none it cannot be`, () => {
+      expect(missing(clipReasons.map((r) => `clip.errors.${r}`))).toEqual([]);
+      expect([...idsUnder(keys, "clip.errors")].filter((r) => !clipReasons.includes(r))).toEqual(
+        [],
+      );
+    });
+
     it(`${lang}: every crew job, auto-tag and built-in profile the backend writes, and no other`, () => {
       for (const [group, words] of Object.entries(VOCAB)) {
         const wanted = words.map((w) => `vocab.${group}.${vocabKey(w)}`);

frontend/src/i18n/locales/en/clip.json

@@ -17,5 +17,15 @@
   "cut": "Cut clip",
   "queued": "The clip is being made — it will be in your downloads",
   "view": "Downloads",
-  "failed": "Couldn’t make the clip"
+  "failed": "Couldn’t make the clip",
+  "errors": {
+    "bad_source": "This video can’t be clipped.",
+    "bad_range": "The clip’s start or end isn’t valid.",
+    "too_short": "A clip is at least a second long.",
+    "too_long": "A clip is at most 10 minutes long.",
+    "bad_audio": "That audio track isn’t available.",
+    "not_found": "This item is no longer in the library.",
+    "media_missing": "The item’s file can’t be reached from here.",
+    "past_end": "The clip runs past the end of the video."
+  }
 }

frontend/src/i18n/locales/hu/clip.json

@@ -17,5 +17,15 @@
   "cut": "Klip vágása",
   "queued": "Készül a klip — a letöltéseid közé kerül",
   "view": "Letöltések",
-  "failed": "Nem sikerült elkészíteni a klipet"
+  "failed": "Nem sikerült elkészíteni a klipet",
+  "errors": {
+    "bad_source": "Ebből a videóból nem lehet klipet vágni.",
+    "bad_range": "A klip eleje vagy vége érvénytelen.",
+    "too_short": "A klip legalább egy másodperc.",
+    "too_long": "A klip legfeljebb 10 perc lehet.",
+    "bad_audio": "Ez a hangsáv nem érhető el.",
+    "not_found": "Ez az elem már nincs a könyvtárban.",
+    "media_missing": "Az elem fájlja innen nem érhető el.",
+    "past_end": "A klip túlnyúlik a videó végén."
+  }
 }

frontend/src/lib/api/core.test.ts

@@ -245,6 +245,22 @@ describe("req — a structured refusal reads in the user's language", () => {
     expect(err.detail).toBeUndefined();
   });
 
+  it.each([
+    ["too_long", "clip.errors.too_long"],
+    ["bad_crop", "clip.errors.bad_crop"],
+  ])("says why a clip was not cut (%s)", async (reason, localized) => {
+    // It read as the generic "couldn't carry out that action" — a 10-minute cap no retry gets past.
+    vi.spyOn(globalThis, "fetch").mockResolvedValue(
+      new Response(JSON.stringify({ detail: { code: "clip", reason } }), {
+        status: 422,
+        headers: { "content-type": "application/json" },
+      }),
+    );
+    await expect(
+      req("/api/downloads/clip", { method: "POST" }, { quiet: true }),
+    ).rejects.toMatchObject({ detail: localized });
+  });
+
   it.each(["quota", "reconnect", "unavailable"])(
     "says what to do about an action YouTube refused (%s)",
     async (reason) => {

frontend/src/lib/api/core.ts

@@ -94,6 +94,9 @@ function localizeDetail(d: unknown): string {
   }
   if (o?.code === "edit")
     return t(`downloads.errors.edit.${o.reason}`, t("downloads.errors.edit.generic"));
+  // A clip the server will not cut (downloads/clip): the range, the frame, the source. An unknown
+  // reason reads as the plain failure rather than a key.
+  if (o?.code === "clip") return t(`clip.errors.${o.reason}`, t("clip.failed"));
   if (o?.code === "cookies")
     return t(`downloads.errors.cookies.${o.reason}`, t("downloads.errors.cookies.generic"));
   // Password sign-in refusals. The card renders the account-shaped ones as a full panel