fix(ui): E31 S2 — the tab names the object, the channel header wraps, the player fits a short window

- The browser tab names the place and the object: PageHeading reports the
  view's own title (lib/documentTitle), so a channel, playlist or any Plex
  view reads "<object> · <module> · Siftlode" however it was opened; the
  Feed is named too; a season adds its show (tabTitle).
- The channel page's tab + action row wraps and lets the tag lane fold into
  "+N": at 1024 it ran past the edge and the page scrolled sideways.
- The YouTube player card's width is capped from the window height less the
  chrome measured under the video: at 133% zoom (685px) it cut its channel row.
- Plex certificate words (Not Rated, Approved, Passed) are named through the
  vocabulary on the info badge, show page, collection, filter and chips.
- DESIGN.md: the zoom target is 125% and 133%, not 200% (decision log).

frontend/src/components/NavigationProvider.tsx

@@ -4,6 +4,7 @@ import { useMe } from "../lib/useMe";
 import { urlWithParams, type Page } from "../lib/urlState";
 import { LOGS_KEYS } from "../lib/logsUrlState";
 import { pageTitleKey } from "../lib/pageMeta";
+import { useDocumentObjectTitle } from "../lib/documentTitle";
 import { setAccountRaw } from "../lib/storage";
 import { setNavigator } from "../lib/nav";
 import {
@@ -164,21 +165,17 @@ export function NavigationProvider({ children }: { children: ReactNode }) {
     if (page !== "feed") setYtSearch(null);
   }
 
-  // Reflect the current module in the browser tab title. Feed = brand only; an open channel page
-  // shows the channel name. Signed out, the page on screen is the public landing whatever `page`
+  // The browser tab names the place and the object in it (DESIGN § Composition, "Where am I"):
+  // "<object> · <module> · Siftlode". The object is the open view's own heading (a channel, a Plex
+  // title, a playlist — `PageHeading` reports it), so a channel opened from a link is named the same
+  // as one opened in the app. Signed out, the page on screen is the public landing whatever `page`
   // says — the tab read "What should I watch?" over the sign-in form (prod UAT 2026-09-19).
   const signedIn = useMe() != null;
+  const objectTitle = useDocumentObjectTitle();
   useEffect(() => {
-    const brand = "Siftlode";
-    const label = !signedIn
-      ? null
-      : channelView
-        ? channelView.name || t("header.channelManager")
-        : page === "feed"
-          ? null
-          : t(pageTitleKey(page));
-    document.title = label ? `${label} · ${brand}` : brand;
-  }, [signedIn, page, channelView, i18n.language, t]);
+    const parts = signedIn ? [objectTitle, t(pageTitleKey(page))] : [];
+    document.title = [...parts.filter(Boolean), "Siftlode"].join(" · ");
+  }, [signedIn, page, objectTitle, i18n.language, t]);
 
   // The page this tab LOADED on. Frozen, because the stamp below belongs to the initial history
   // entry: every later page change writes its own entry through setPage.