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/i18n/locales/en/feed.json

@@ -75,6 +75,9 @@
     "clearNow": "Clear now",
     "cleared_one": "Cleared {{count}} result",
     "cleared_other": "Cleared {{count}} results",
-    "showHint": "How many results to fetch at a time — “Load more” pulls another batch of this size."
+    "showHint": "How many results to fetch at a time — “Load more” pulls another batch of this size.",
+    "notRunTitle": "This search hasn't run again",
+    "notRunBody": "A YouTube API search spends 100 units of the shared daily quota, so a reload or a link doesn't start one by itself.",
+    "runAgain": "Search YouTube again"
   }
 }

frontend/src/i18n/locales/hu/feed.json

@@ -75,6 +75,9 @@
     "clearNow": "Törlés most",
     "cleared_one": "{{count}} találat törölve",
     "cleared_other": "{{count}} találat törölve",
-    "showHint": "Hány találatot szerezzen egyszerre — a „Továbbiak betöltése” ennyivel tölt tovább."
+    "showHint": "Hány találatot szerezzen egyszerre — a „Továbbiak betöltése” ennyivel tölt tovább.",
+    "notRunTitle": "Ez a keresés nem futott újra",
+    "notRunBody": "Egy YouTube API-keresés 100 egységet fogyaszt a közös napi kvótából, ezért újratöltés vagy link nem indít el egyet magától.",
+    "runAgain": "Keresés újra a YouTube-on"
   }
 }