diff --git a/backend/server.py b/backend/server.py
index f6161e9..2c2f891 100644
--- a/backend/server.py
+++ b/backend/server.py
@@ -630,8 +630,8 @@ async def cancel_job(job_id: str, user: dict = Depends(require_admin)):
         raise HTTPException(status_code=400, detail="Cannot cancel a running job")
     await db.transcode_queue.update_one({"id": job_id}, {"$set": {"status": "cancelled", "finished_at": datetime.now(timezone.utc).isoformat()}})
     if job["status"] == "pending":
-        # Reset movie hls_status so a new transcode can be triggered
-        await db.movies.update_one({"id": job["movie_id"]}, {"$set": {"hls_status": None}})
+        # Reset movie hls_status AND clear stale hls_path so the row no longer shows as transcoded
+        await db.movies.update_one({"id": job["movie_id"]}, {"$set": {"hls_status": None, "hls_path": None}})
     return {"ok": True}
 
 
diff --git a/frontend/src/pages/TranscodeQueue.jsx b/frontend/src/pages/TranscodeQueue.jsx
index c835a45..a9128ef 100644
--- a/frontend/src/pages/TranscodeQueue.jsx
+++ b/frontend/src/pages/TranscodeQueue.jsx
@@ -113,6 +113,11 @@ export default function TranscodeQueue() {
               </span>
               <span className="col-span-2 text-xs text-[#8A8A8A]">{new Date(j.created_at).toLocaleString()}</span>
               <div className="col-span-1 flex justify-end gap-2">
+                {j.status === "running" && (
+                  <button disabled className="text-[#444] cursor-not-allowed" title="Cannot cancel a running job" aria-label="Running">
+                    <X size={14} strokeWidth={1.5} />
+                  </button>
+                )}
                 {j.status === "pending" && (
                   <button onClick={() => cancel(j.id)} className="text-[#8A8A8A] hover:text-[#fca5a5]" data-testid={`cancel-${j.id}`} aria-label="Cancel">
                     <X size={14} strokeWidth={1.5} />
diff --git a/memory/PRD.md b/memory/PRD.md
index 291caf8..c513ffe 100644
--- a/memory/PRD.md
+++ b/memory/PRD.md
@@ -44,17 +44,25 @@
 - **Admin Settings page** for TMDB + Radarr config with masked inputs + connection test
 
 ### Phase 3 (2026-04-29)
-- **Adaptive bitrate (ABR) HLS**: admin can choose Quick (stream-copy, single-rate, instant) OR ABR (re-encode to 360p/480p/720p/1080p with master playlist)
-- **Smart variant selection**: ABR ladder auto-trims to source resolution (no upscaling)
-- **Auth-aware playlist serving**: master.m3u8 and per-variant playlists are rewritten on serve to inject `?auth=token` into all relative URLs, so hls.js segment requests stay authenticated
-- **Quality badge** in admin row shows whether HLS is `Quick` or `ABR`
-- **Defensive `-pix_fmt yuv420p`** ensures encoder works across all source chroma formats
-- Verified end-to-end: 720p source → 3 variants (720p/480p/360p) generated in seconds with proper master playlist
+- **Adaptive bitrate (ABR) HLS**: admin chooses Quick (stream-copy, instant) or ABR (re-encode to 360p/480p/720p/1080p with master playlist)
+- Smart variant selection: ladder auto-trims to source resolution (no upscaling)
+- Auth-aware playlist serving rewrites `?auth=` into every relative URL so hls.js segment requests stay authenticated
+- Quality badge in admin row shows `HLS done · Quick` or `HLS done · ABR`
+- Defensive `-pix_fmt yuv420p` ensures encoder works across all source chroma formats
+
+### Phase 4 (2026-04-29)
+- **Background Transcode Queue** with persistent storage in MongoDB
+- Single FIFO worker started at backend boot; processes one job at a time
+- ffmpeg runs at **low CPU priority** (`nice -n 19`) so streaming + UI stay snappy during transcodes
+- **Auto-transcode** toggle in Settings: Off / Quick / ABR — applied to every new upload AND Radarr import
+- **Pause/resume** queue, **cancel** pending jobs, **retry** failed/cancelled jobs, **clear** finished history
+- **Stat tiles** (pending/running/done/failed/cancelled) on `/admin/queue`
+- **Crash recovery**: stuck `running` jobs are reset to `failed` on backend restart
+- Cancel of a pending job clears `hls_path` to avoid stale references
 
 ## Backlog (P1)
 - Sonarr (TV shows): requires episodes/seasons data model — significant addition
 - Subtitle search via OpenSubtitles API
-- Multi-bitrate HLS (current is single-rate stream-copy)
 - Trakt.tv sync (mark watched, ratings)
 - DLNA/Chromecast casting