feat(design): a channel's and a Plex playlist's one action list (C1) — the row's "…", Delete + undo, an action toast's 8 s floor (E28 S3e2)

- Channels: the row's full-history, hide and unsubscribe buttons become its "…" at the row end
  (useChannelActions: open, pin, YouTube, copy name / link, full history or the admin reset,
  hide with an undo toast, unsubscribe behind its danger confirm); the card layout docks the "…"
  beside the name (ChannelLayoutGrid moreKey). The admin reset's confirm now names the reset.
- Plex playlist page: a title, a show group and a season each open the page's one row menu (a
  title's is its usePlexCardActions list plus the removal); no X at rest; removals take an undo
  toast whose Undo puts every row back at its own index in one request (bulk add `positions`);
  j/k walk the visible rows, Delete removes the walked one; rename and delete in the header's "…".
- notify: a toast with an action lives at least 8 s (the owner's call), whatever the toast setting.

frontend/src/lib/api/plex.ts

@@ -558,13 +558,16 @@ export const plexApi = {
       method: "POST",
       body: JSON.stringify({ title, item_rating_key }),
     }),
+  /** `positions` (one per key, an index over the ordered rows) puts removed rows back where they
+   *  stood — the list page's Undo, in one request; without it the keys are appended. */
   plexPlaylistAddBulk: (
     id: number,
     itemRks: string[],
+    positions?: number[],
   ): Promise<{ added: number; item_count: number }> =>
     req(`/api/plex/playlists/${id}/items/bulk`, {
       method: "POST",
-      body: JSON.stringify({ item_rating_keys: itemRks }),
+      body: JSON.stringify({ item_rating_keys: itemRks, ...(positions ? { positions } : {}) }),
     }),
   plexPlaylistRemoveBulk: (
     id: number,

frontend/src/lib/notifications.actionTtl.dom.test.ts

@@ -0,0 +1,52 @@
+// @vitest-environment jsdom
+//
+// A toast with an action (the list page's "Undo") outlives a short toast setting: its button is the
+// only way back, so it gets ACTION_TTL_MIN at least (owner, E28 S3e2). The setting still wins when it
+// is longer, "never" still means never, and a plain toast keeps the reader's time.
+import { describe, it, expect, afterEach, beforeEach, vi } from "vitest";
+import {
+  ACTION_TTL_MIN,
+  clearAll,
+  configureNotifications,
+  getActiveToasts,
+  notify,
+} from "./notifications";
+
+beforeEach(() => vi.useFakeTimers());
+afterEach(() => {
+  clearAll();
+  configureNotifications({ durationMs: 6000 });
+  vi.useRealTimers();
+});
+
+const undo = { label: "Undo", onClick: () => {} };
+const shown = (id: number) => getActiveToasts().some((n) => n.id === id);
+
+describe("an action toast's lifetime", () => {
+  it("stays for the floor when the reader's toasts last 3 s", () => {
+    configureNotifications({ durationMs: 3000 });
+    const plain = notify({ message: "plain" });
+    const withUndo = notify({ message: "removed", action: undo });
+    vi.advanceTimersByTime(3001);
+    expect(shown(plain)).toBe(false);
+    expect(shown(withUndo)).toBe(true);
+    vi.advanceTimersByTime(ACTION_TTL_MIN - 3001);
+    expect(shown(withUndo)).toBe(false);
+  });
+
+  it("keeps a longer setting", () => {
+    configureNotifications({ durationMs: 12000 });
+    const id = notify({ message: "removed", action: undo });
+    vi.advanceTimersByTime(ACTION_TTL_MIN + 1);
+    expect(shown(id)).toBe(true);
+    vi.advanceTimersByTime(12000 - ACTION_TTL_MIN);
+    expect(shown(id)).toBe(false);
+  });
+
+  it("never dismisses when the reader chose never", () => {
+    configureNotifications({ durationMs: 0 });
+    const id = notify({ message: "removed", action: undo });
+    vi.advanceTimersByTime(60000);
+    expect(shown(id)).toBe(true);
+  });
+});

frontend/src/lib/notifications.ts

@@ -92,6 +92,10 @@ const HISTORY_KEY = LS.notifHistory;
 const SETTINGS_KEY = LS.notifSettings;
 const MAX_HISTORY = 100;
 const ERROR_TTL = 15000;
+// A toast that carries an action (an "Undo") lives at least this long, whatever the reader's toast
+// time: its button is the only way back, and a 3 s toast leaves no time to reach it (owner, E28).
+// The setting still decides for longer, and "never" still means never.
+export const ACTION_TTL_MIN = 8000;
 
 // 6b: per-account notification settings (persisted by the Settings panel into the
 // server `preferences`, mirrored to localStorage so they apply before login).
@@ -269,7 +273,9 @@ export function notify(input: NotifyInput): number {
       : level === "error" || level === "fatal"
         ? ERROR_TTL
         : config.durationMs > 0
-          ? config.durationMs
+          ? input.action
+            ? Math.max(config.durationMs, ACTION_TTL_MIN)
+            : config.durationMs
           : undefined;
 
   // Coalesce a rapid burst of identical notifications (same level+title+message within the