feat(inbox): add navigation links to watched and scheduler notices

Extend the reload-safe meta+link pattern (introduced for "Subscribed") to
more inbox entries, so every notice that can point somewhere does:

- A "Marked watched" activity notice now offers "Find in feed" (jumping to
  the feed filtered to Watched + that channel), alongside Unwatch — matching
  what the "Hidden" notice already does. VideoWatchedMeta carries the
  channel, and locate() handles both hidden and watched.
- A scheduler job-completion notice (System) now offers "Open Scheduler",
  jumping to the dashboard.

Maintenance notices reference already-removed videos, so they stay
informational with nothing to navigate to.

frontend/src/components/Feed.tsx

@@ -174,7 +174,13 @@ export default function Feed({
                 ? i18n.t("feed.markedWatchedNamed", { title: v.title })
                 : i18n.t("feed.markedWatched"),
               action: { label: i18n.t("feed.unwatch"), onClick: () => onState(id, "new") },
-              meta: { kind: "video-watched", videoId: id, title: v?.title ?? "this video" },
+              meta: {
+                kind: "video-watched",
+                videoId: id,
+                title: v?.title ?? "this video",
+                channelId: v?.channel_id ?? "",
+                channelName: v?.channel_title ?? "",
+              },
             });
           } else if (status === "new") {
             // Unhide / unwatch (from a card, the toast's Undo, or the center): quietly resolve

frontend/src/components/NotificationsPanel.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useSyncExternalStore } from "react";
 import { useTranslation } from "react-i18next";
 import { useMutation, useQueryClient } from "@tanstack/react-query";
-import { Bell, Check, CheckCheck, ExternalLink, Eye, RotateCcw, Search, Trash2, Tv, X } from "lucide-react";
+import { Activity, Bell, Check, CheckCheck, ExternalLink, Eye, RotateCcw, Search, Trash2, Tv, X } from "lucide-react";
 import { api, type AppNotification, type FeedFilters } from "../lib/api";
 import { useLiveQuery } from "../lib/useLiveQuery";
 import {
@@ -94,11 +94,12 @@ export default function NotificationsPanel({
     clearMut.mutate();
   }
 
-  // "Find in feed" / undo, ported from the old bell.
-  function locateHidden(meta: VideoHiddenMeta) {
+  // "Find in feed" / undo, ported from the old bell. Works for both hidden and watched
+  // notices — jump to the feed filtered to that state and the video's channel.
+  function locate(meta: VideoHiddenMeta | VideoWatchedMeta) {
     setFilters({
       ...filters,
-      show: "hidden",
+      show: meta.kind === "video-hidden" ? "hidden" : "watched",
       channelId: meta.channelId || undefined,
       channelName: meta.channelName || undefined,
     });
@@ -168,6 +169,7 @@ export default function NotificationsPanel({
                     t={t}
                     onRead={() => readMut.mutate(n.id)}
                     onDismiss={() => dismissMut.mutate(n.id)}
+                    onOpenScheduler={() => setPage("scheduler")}
                   />
                 ))}
               </div>
@@ -184,7 +186,7 @@ export default function NotificationsPanel({
                     key={n.id}
                     n={n}
                     t={t}
-                    onFind={locateHidden}
+                    onFind={locate}
                     onRevert={revertState}
                     onFocusChannel={onFocusChannel}
                     onRemove={() => removeClient(n.id)}
@@ -204,11 +206,13 @@ function NotificationRow({
   t,
   onRead,
   onDismiss,
+  onOpenScheduler,
 }: {
   n: AppNotification;
   t: (k: string, o?: any) => string;
   onRead: () => void;
   onDismiss: () => void;
+  onOpenScheduler: () => void;
 }) {
   // The maintenance producer ships the affected videos in `data.videos`; list a few titles.
   const videos: { id: string; title: string | null }[] = Array.isArray(n.data?.videos)
@@ -261,6 +265,15 @@ function NotificationRow({
             )}
           </ul>
         )}
+        {isScheduler && (
+          <button
+            onClick={onOpenScheduler}
+            className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline mt-1.5"
+          >
+            <Activity className="w-3.5 h-3.5" />
+            {t("inbox.openScheduler")}
+          </button>
+        )}
       </div>
       <div className="flex items-center gap-1 shrink-0">
         {!n.read && (
@@ -296,7 +309,7 @@ function ClientActivityRow({
 }: {
   n: ClientNotif;
   t: (k: string, o?: any) => string;
-  onFind: (meta: VideoHiddenMeta) => void;
+  onFind: (meta: VideoHiddenMeta | VideoWatchedMeta) => void;
   onRevert: (meta: VideoHiddenMeta | VideoWatchedMeta) => void;
   onFocusChannel: (name: string) => void;
   onRemove: () => void;
@@ -342,6 +355,13 @@ function ClientActivityRow({
           </div>
         ) : watched ? (
           <div className="flex items-center gap-3 mt-1">
+            <button
+              onClick={() => onFind(watched)}
+              className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline"
+            >
+              <Search className="w-3.5 h-3.5" />
+              {t("notifications.findInFeed")}
+            </button>
             <button
               onClick={() => onRevert(watched)}
               className="flex items-center gap-1 text-accent text-sm font-semibold hover:underline"