fix(playlists-ui): surface YouTube 403s + rollback remove; drop dup name/import

BUGS:
- push/sync/revert (PF1/PF2/PF4) swallowed every failure into a generic warning,
  so a missing-write-scope 403 gave no hint and no "Connect your YouTube account"
  affordance (unlike Channels). Route all three through notifyYouTubeActionError
  (no wizard handle on this screen, so message-only for the 403).
- removeItem (PF5) reset the order optimistically then awaited the delete with no
  catch: a failed call left the row gone locally (and an unhandled rejection).
  Now resync via refreshAll on either path (api.req surfaces the error dialog).

CLEANUP:
- Drop the dead `Check` lucide import (PC6; only AddToPlaylist uses it).
- Use the module plName(detail) helper instead of the inline watch_later-vs-name
  ternary that shadowed it in push/revert (PC7).

tsc green, localdev boots healthy.

frontend/src/components/Playlists.tsx

@@ -19,7 +19,6 @@ import { CSS } from "@dnd-kit/utilities";
 import {
   ArrowDown,
   ArrowUp,
-  Check,
   ExternalLink,
   GripVertical,
   ListPlus,
@@ -37,6 +36,7 @@ import {
 import { api, type Playlist, type Video } from "../lib/api";
 import { formatDuration } from "../lib/format";
 import { notify } from "../lib/notifications";
+import { notifyYouTubeActionError } from "../lib/youtubeErrors";
 import { getAccountRaw, LS, readAccountMerged, setAccountRaw, writeAccount } from "../lib/storage";
 import { useUndoable } from "../lib/useUndoable";
 const PlayerModal = lazy(() => import("./PlayerModal"));
@@ -347,14 +347,13 @@ export default function Playlists({ canWrite }: { canWrite: boolean }) {
       danger: true,
     });
     if (!ok) return;
-    const plName = detail.kind === "watch_later" ? t("playlists.watchLater") : detail.name;
     setReverting(true);
     try {
       await api.revertPlaylist(selectedId);
       refreshAll();
-      notify({ level: "success", message: t("playlists.revertDone", { name: plName }) });
-    } catch {
-      notify({ level: "warning", message: t("playlists.revertFailed") });
+      notify({ level: "success", message: t("playlists.revertDone", { name: plName(detail) }) });
+    } catch (e) {
+      notifyYouTubeActionError(e, t("playlists.revertFailed"));
     } finally {
       setReverting(false);
     }
@@ -362,12 +361,11 @@ export default function Playlists({ canWrite }: { canWrite: boolean }) {
 
   async function pushToYoutube() {
     if (selectedId == null || !detail || pushing) return;
-    const plName = detail.kind === "watch_later" ? t("playlists.watchLater") : detail.name;
     setPushing(true);
     try {
       const plan = await api.playlistPushPlan(selectedId);
       if (plan.action === "update" && !plan.to_insert && !plan.to_delete && !plan.to_reorder) {
-        notify({ level: "info", message: t("playlists.pushUpToDate", { name: plName }) });
+        notify({ level: "info", message: t("playlists.pushUpToDate", { name: plName(detail) }) });
         return;
       }
       if (!plan.affordable) {
@@ -406,10 +404,10 @@ export default function Playlists({ canWrite }: { canWrite: boolean }) {
       if (r.failures.length) {
         notify({ level: "warning", message: t("playlists.pushPartial", { count: r.failures.length }) });
       } else {
-        notify({ level: "success", message: t("playlists.pushDone", { name: plName }) });
+        notify({ level: "success", message: t("playlists.pushDone", { name: plName(detail) }) });
       }
-    } catch {
-      notify({ level: "warning", message: t("playlists.pushFailed") });
+    } catch (e) {
+      notifyYouTubeActionError(e, t("playlists.pushFailed"));
     } finally {
       setPushing(false);
     }
@@ -423,8 +421,8 @@ export default function Playlists({ canWrite }: { canWrite: boolean }) {
       qc.invalidateQueries({ queryKey: ["playlists"] });
       qc.invalidateQueries({ queryKey: ["playlist"] });
       notify({ level: "success", message: t("playlists.syncedToast", { count: r.synced }) });
-    } catch {
-      notify({ level: "warning", message: t("playlists.syncFailed") });
+    } catch (e) {
+      notifyYouTubeActionError(e, t("playlists.syncFailed"));
     } finally {
       setSyncing(false);
     }
@@ -463,8 +461,14 @@ export default function Playlists({ canWrite }: { canWrite: boolean }) {
     const next = items.filter((v) => v.id !== videoId);
     order.reset(next);
     lastSetRef.current = idsKey(next);
+    try {
       await api.removeFromPlaylist(selectedId, videoId);
       refreshAll();
+    } catch {
+      // The optimistic removal above didn't stick — resync from the server to restore the row.
+      // api.req already surfaced the error to the user via the global error dialog.
+      refreshAll();
+    }
   }
 
   async function saveRename() {