Add confirm+stop to Library Cleanup scan; branded album art placeholder

- Library Cleanup scan is now a real background job (POST .../start,
  GET .../status, POST .../stop) instead of one long synchronous request,
  so a Stop button can actually abandon it instead of just waiting.
  Frontend confirms before starting (explains it can take a minute+)
  and polls status while running.
- New shared AlbumArt component: shows real art when available, otherwise
  a branded "Streamhoard" placeholder instead of a bare icon in an empty
  box. Used in the Music grid, album detail header, and the player bar —
  swaps to real art automatically once enrichment/a manual edit sets it.

frontend/src/components/AlbumArt.jsx

@@ -0,0 +1,20 @@
+// Shows real album art when a URL is available; otherwise a branded placeholder instead of an
+// empty box. Once musicbrainz enrichment (or a manual edit) sets album_art_url, callers just
+// pass the new url and this swaps over automatically — no separate "loaded" state to manage.
+export default function AlbumArt({ url, size = "lg", className = "" }) {
+  if (url) {
+    return <img src={url} alt="" className={`w-full h-full object-cover ${className}`} />;
+  }
+  const small = size === "sm";
+  return (
+    <div className={`w-full h-full flex items-center justify-center bg-gradient-to-br from-[#161616] to-[#0a0a0a] ${className}`}>
+      {small ? (
+        <span className="font-display font-black text-[#3a3a3a] text-lg select-none">S<span className="text-[#D9381E]">.</span></span>
+      ) : (
+        <span className="font-display font-black tracking-tighter text-[#3a3a3a] text-sm sm:text-base select-none text-center px-2">
+          Stream<span className="text-[#D9381E]">hoard</span>
+        </span>
+      )}
+    </div>
+  );
+}

frontend/src/components/MusicPlayerBar.jsx

@@ -1,6 +1,7 @@
 import { useEffect, useState } from "react";
-import { Play, Pause, SkipBack, SkipForward, Music2, Speaker } from "lucide-react";
+import { Play, Pause, SkipBack, SkipForward, Speaker } from "lucide-react";
 import { useMusicPlayer } from "../lib/musicPlayer";
+import AlbumArt from "./AlbumArt";
 
 const fmt = (s) => {
   if (!s || !isFinite(s)) return "0:00";
@@ -33,8 +34,8 @@ export default function MusicPlayerBar() {
   return (
     <div className="fixed bottom-0 left-0 right-0 z-50 bg-[#0a0a0a]/95 backdrop-blur border-t border-[#222] px-4 md:px-8 py-3" data-testid="music-player-bar">
       <div className="max-w-[1500px] mx-auto flex items-center gap-4">
-        <div className="w-10 h-10 shrink-0 bg-[#0F0F0F] flex items-center justify-center overflow-hidden">
-          {current.album_art_url ? <img src={current.album_art_url} alt="" className="w-full h-full object-cover" /> : <Music2 size={18} className="text-[#8A8A8A]" />}
+        <div className="w-10 h-10 shrink-0 bg-[#0F0F0F] overflow-hidden">
+          <AlbumArt url={current.album_art_url} size="sm" />
         </div>
         <div className="min-w-0 w-40 md:w-56">
           <p className="text-white text-sm truncate">{current.title}</p>

frontend/src/pages/AlbumDetail.jsx

@@ -3,6 +3,7 @@ import { useParams, useNavigate } from "react-router-dom";
 import api from "../lib/api";
 import { Play, Pause, ArrowLeft, Music2 } from "lucide-react";
 import { useMusicPlayer } from "../lib/musicPlayer";
+import AlbumArt from "../components/AlbumArt";
 
 export default function AlbumDetail() {
   const { artist, album } = useParams();
@@ -40,8 +41,8 @@ export default function AlbumDetail() {
         </button>
 
         <div className="flex items-center gap-6 mb-10">
-          <div className="w-32 h-32 shrink-0 bg-[#0F0F0F] flex items-center justify-center overflow-hidden">
-            {artUrl ? <img src={artUrl} alt="" className="w-full h-full object-cover" /> : <Music2 size={36} strokeWidth={1.5} className="text-[#8A8A8A]" />}
+          <div className="w-32 h-32 shrink-0 bg-[#0F0F0F] overflow-hidden">
+            <AlbumArt url={artUrl} />
           </div>
           <div>
             <span className="text-xs uppercase tracking-[0.3em] text-[#D9381E]">Album</span>

frontend/src/pages/LibraryCleanup.jsx

@@ -1,7 +1,7 @@
-import { useEffect, useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import api from "../lib/api";
 import { toast } from "sonner";
-import { RefreshCcw, Trash2, Wrench, ShieldCheck } from "lucide-react";
+import { RefreshCcw, Trash2, Wrench, ShieldCheck, Square } from "lucide-react";
 
 const CATEGORIES = [
   { key: "missing_files", label: "Missing Files", desc: "Database record exists but the file is gone from disk.", action: "Remove record" },
@@ -15,21 +15,58 @@ const CATEGORIES = [
 
 export default function LibraryCleanup() {
   const [findings, setFindings] = useState(null);
-  const [loading, setLoading] = useState(false);
+  const [running, setRunning] = useState(false);
   const [fixing, setFixing] = useState({});
+  const pollRef = useRef(null);
+
+  const checkStatus = async () => {
+    const { data } = await api.get("/library/cleanup/scan/status");
+    setRunning(data.running);
+    if (data.error) toast.error(`Scan failed: ${data.error}`);
+    if (data.findings) setFindings(data.findings);
+    return data.running;
+  };
+
+  const startPolling = () => {
+    if (pollRef.current) return;
+    pollRef.current = setInterval(async () => {
+      const stillRunning = await checkStatus();
+      if (!stillRunning) {
+        clearInterval(pollRef.current);
+        pollRef.current = null;
+      }
+    }, 2000);
+  };
+
+  useEffect(() => {
+    checkStatus().then((isRunning) => { if (isRunning) startPolling(); });
+    return () => { if (pollRef.current) clearInterval(pollRef.current); };
+  }, []);
 
   const scan = async () => {
-    setLoading(true);
+    if (!window.confirm(
+      "This checks every movie, episode, and track's file against the NAS, which can take a while on a large library (roughly a minute or more) since each check is a network round trip. It runs in the background and won't block the rest of the app — you can navigate away or stop it anytime. Continue?"
+    )) return;
     try {
-      const { data } = await api.get("/library/cleanup/scan");
-      setFindings(data);
+      await api.post("/library/cleanup/scan/start");
+      setRunning(true);
+      setFindings(null);
+      startPolling();
     } catch (err) {
-      toast.error(err.response?.data?.detail || "Cleanup scan failed");
-    } finally {
-      setLoading(false);
+      toast.error(err.response?.data?.detail || "Could not start scan");
+    }
+  };
+
+  const stopScan = async () => {
+    try {
+      await api.post("/library/cleanup/scan/stop");
+      setRunning(false);
+      if (pollRef.current) { clearInterval(pollRef.current); pollRef.current = null; }
+      toast.success("Scan stopped");
+    } catch (err) {
+      toast.error(err.response?.data?.detail || "Could not stop scan");
     }
   };
-  useEffect(() => { scan(); }, []);
 
   const fix = async (category, items) => {
     if (items.length === 0) return;
@@ -57,10 +94,17 @@ export default function LibraryCleanup() {
         </p>
 
         <div className="mt-8 flex items-center gap-4">
-          <button onClick={scan} disabled={loading} className="flex items-center gap-2 border border-[#222] hover:border-white text-[#8A8A8A] hover:text-white px-5 py-2 text-xs uppercase tracking-[0.2em] transition-colors disabled:opacity-50" data-testid="cleanup-scan">
-            <RefreshCcw size={14} strokeWidth={1.5} className={loading ? "animate-spin" : ""} /> {loading ? "Scanning…" : "Rescan"}
-          </button>
-          {findings && (
+          {running ? (
+            <button onClick={stopScan} className="flex items-center gap-2 border border-[#D9381E] text-[#D9381E] hover:bg-[#D9381E]/10 px-5 py-2 text-xs uppercase tracking-[0.2em] transition-colors" data-testid="cleanup-stop">
+              <Square size={12} strokeWidth={1.5} fill="currentColor" /> Stop Scan
+            </button>
+          ) : (
+            <button onClick={scan} className="flex items-center gap-2 border border-[#222] hover:border-white text-[#8A8A8A] hover:text-white px-5 py-2 text-xs uppercase tracking-[0.2em] transition-colors" data-testid="cleanup-scan">
+              <RefreshCcw size={14} strokeWidth={1.5} /> {findings ? "Rescan" : "Scan Library"}
+            </button>
+          )}
+          {running && <span className="text-xs text-[#fcd34d] animate-pulse" data-testid="cleanup-running">Scanning… this can take a minute</span>}
+          {!running && findings && (
             <span className="flex items-center gap-2 text-sm" data-testid="cleanup-summary">
               {totalIssues === 0 ? (
                 <><ShieldCheck size={16} className="text-[#86efac]" /> <span className="text-[#86efac]">No issues found</span></>
@@ -106,12 +150,17 @@ export default function LibraryCleanup() {
               </div>
             );
           })}
-          {findings && totalIssues === 0 && (
+          {!running && findings && totalIssues === 0 && (
             <div className="text-center py-16 text-[#8A8A8A]">
               <ShieldCheck size={40} strokeWidth={1.5} className="mx-auto mb-4 text-[#86efac]" />
               Library is clean — no missing files, orphaned records, or stuck jobs.
             </div>
           )}
+          {!running && !findings && (
+            <div className="text-center py-16 text-[#8A8A8A]">
+              Click "Scan Library" above to check for issues.
+            </div>
+          )}
         </div>
       </div>
     </div>

frontend/src/pages/Music.jsx

@@ -2,6 +2,7 @@ import { useEffect, useMemo, useState } from "react";
 import { useNavigate } from "react-router-dom";
 import api from "../lib/api";
 import { Music2 } from "lucide-react";
+import AlbumArt from "../components/AlbumArt";
 
 export default function Music() {
   const [tracks, setTracks] = useState([]);
@@ -45,11 +46,7 @@ export default function Music() {
               onClick={() => nav(`/music/album/${encodeURIComponent(a.artist)}/${encodeURIComponent(a.album)}`)}
               className="group relative aspect-square overflow-hidden bg-[#0F0F0F] transition-transform duration-300 hover:scale-105 focus:outline-none focus:ring-2 focus:ring-[#D9381E]"
               data-testid={`album-card-${a.artist}-${a.album}`}>
-              {a.album_art_url ? (
-                <img src={a.album_art_url} alt={a.album} loading="lazy" className="w-full h-full object-cover" />
-              ) : (
-                <div className="w-full h-full flex items-center justify-center"><Music2 size={32} strokeWidth={1.5} className="text-[#8A8A8A]" /></div>
-              )}
+              <AlbumArt url={a.album_art_url} />
               <div className="absolute inset-x-0 bottom-0 bg-gradient-to-t from-black to-transparent p-3 opacity-0 group-hover:opacity-100 transition-opacity duration-300">
                 <p className="text-white text-sm truncate">{a.album}</p>
                 <p className="text-[10px] uppercase tracking-[0.2em] text-[#8A8A8A] truncate">{a.artist} · {a.count} tracks</p>