Add a setting to hide the quarantine from Plex

Settings -> Media servers -> "Hide quarantine from Plex" writes a
.plexignore into every pair's quarantine folder (.playlink-trash by
default), with patterns for every folder depth quarantined files live
at. Quarantine folders opened later get the file automatically.

The file carries a marker line: turning the option off removes only
playlink's own file, and an existing .plexignore written by someone else
is never overwritten or deleted (reported instead). Writes go through a
temporary file and a rename.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/api.ts

@@ -33,6 +33,7 @@ export type Info = {
   allowed_roots: string[];
   default_extensions: string[];
   dry_run: boolean;
+  plex_ignore: boolean;
 };
 
 export type Job = {

web/src/pages/Settings.tsx

@@ -15,6 +15,17 @@ export function SettingsPage() {
     mutationFn: (v: boolean) => api.put("/settings", { dry_run: v }),
     onSuccess: () => qc.invalidateQueries({ queryKey: ["info"] }),
   });
+  const plex = useMutation({
+    mutationFn: (v: boolean) =>
+      api.put<{ plex_ignore: boolean; results?: { pair: string; path: string; error?: string }[] }>("/settings", { plex_ignore: v }),
+    onSuccess: (res) => {
+      qc.invalidateQueries({ queryKey: ["info"] });
+      const failed = (res.results ?? []).filter((r) => r.error);
+      if (failed.length > 0) failed.forEach((r) => toast("err", `${r.pair}: ${r.error}`));
+      else toast("ok", res.plex_ignore ? "Added .plexignore to every quarantine folder." : "Removed playlink's .plexignore files.");
+    },
+    onError: (e) => toast("err", e.message),
+  });
   const pw = useMutation({
     mutationFn: () => api.post("/auth/password", { current: cur, new: next }),
     onSuccess: () => {
@@ -52,6 +63,21 @@ export function SettingsPage() {
         </div>
       </Card>
 
+      <Card className="space-y-3 p-5">
+        <h2 className="font-semibold">Media servers</h2>
+        <Toggle
+          checked={info.data?.plex_ignore ?? false}
+          onChange={(v) => plex.mutate(v)}
+          label={<span className="font-medium">Hide quarantine from Plex</span>}
+        />
+        <p className="text-sm text-muted">
+          Adds a <code className="mono">.plexignore</code> file to each library pair's quarantine folder (by default{" "}
+          <code className="mono">.playlink-trash</code> in the slave library), so Plex doesn't pick up quarantined songs as duplicates. New
+          quarantine folders get it automatically. Turning this off removes the file again, but only if playlink created it: a{" "}
+          <code className="mono">.plexignore</code> of your own is never changed.
+        </p>
+      </Card>
+
       <Card className="space-y-2 p-5">
         <h2 className="font-semibold">Environment</h2>
         <div className="text-sm">