feat(web): retry a needs-attention job from The Floor

Add POST /api/requests/[id]/retry: 404 if the request/job is missing,
400 if the job isn't in needs_attention, otherwise clears the job's
stale candidates and resets it to state=requested/currentStage=intake
(error/claimedAt cleared) plus request status=pending, in a
transaction, so the worker's requested-only claim re-picks it up.
Wire a Retry button into the attention-row note on the Floor.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/queue.tsx

@@ -72,6 +72,14 @@ export function Queue() {
     return () => clearInterval(id);
   }, []);
 
+  async function retry(id: string) {
+    const res = await fetch(`/api/requests/${id}/retry`, { method: "POST" });
+    if (res.ok) {
+      toast("Retrying…");
+      refresh();
+    }
+  }
+
   async function submit(e: React.FormEvent) {
     e.preventDefault();
     if (!artist.trim() || !album.trim()) return;
@@ -149,10 +157,14 @@ export function Queue() {
                 meta = undefined;
               }
 
-              const note = attention
-                ? j.error?.trim() ||
-                  "No source met the quality cutoff, or the pipeline stalled. Retry the request, or lower the cutoff for this release."
-                : undefined;
+              const note = attention ? (
+                <>
+                  {j.error?.trim() || "No source met the quality cutoff, or the pipeline stalled."}{" "}
+                  <button className="btn sm" onClick={() => retry(r.id)}>
+                    Retry
+                  </button>
+                </>
+              ) : undefined;
 
               const stageLabel =
                 attention || j.state === "matching" || j.state === "matched" ? undefined : j.currentStage;