feat(nav): the live YouTube search and Home's budget are named in the address

A YouTube search is `?yt=<term>` (+ `ytn` for a non-default count), so a reload, a link
or Back/Forward reopens it. It runs by itself only where it costs no quota: the free page
scrape, a search asked for in this document, or results still cached. An API search
reopened any other way shows its term and waits for "Search YouTube again".

Home's time budget is `hb`; the question's draw stays on the history entry.

An e2e spec opens every page's bookmark in a fresh browser context; CLAUDE.md and
docs/development.md name the module URL codec as the place for view state.

frontend/src/modules/channels/ChannelsProvider.tsx

@@ -185,7 +185,7 @@ export function ChannelsProvider({ children }: { children: ReactNode }) {
     // column filter (the whole map is set fresh) so no stale funnel hides the rows we're sent to see.
     setFilters({ sync: "needsFull" });
     setView("subscribed"); // the sync filter applies to the subscriptions tab
-    setFiltersResetToken((n) => n + 1); // also clear the ephemeral name search + tag chips
+    setFiltersResetToken((n) => n + 1); // also clear the name search + tag chips
     setPage("channels");
   }, [setFilters, setView, setPage]);