fix(nav): the address follows the view through overlays, reloads and Back (review round 1)

- A URL mirror names the view again on every entry Back or Forward lands on, so a change made
  under a dialog, a drawer or a sub-view is not undone by the next reload.
- A view pushed from the entry a reload under a dialog started from no longer inherits its overlay
  mark; a reload under two overlays closes onto the page in one step.
- The linked player reopens over a live search, gives itself up when its list moves first, and
  plays alone over an emptied playlist; a capped Files list keeps the link it cannot resolve.
- The Feed press over a channel ends the search; leaving a search ends its asked mark; Files and
  Playlists searches end with their page; the feed always names its view and debounces its search.
- Search-box keys are declared per module and kept out of the client log below TRACE.
- Writers outside lib/ go through codecs; the URL contract scans computed keys, overlay writers and
  two-line reads, and holds every page to a bookmark round trip (Config, Activity, Playlists and the
  Files sort and viewer added).

frontend/src/features/navigation/moduleRegistry.ts

@@ -55,6 +55,10 @@ const ALL_URL_KEYS: readonly string[] = ALL.flatMap((m) => m.urlKeys);
 export function moduleUrlKeys(): readonly string[] {
   return ALL_URL_KEYS;
 }
+/** Every module's address-bar keys that carry typed text — what the client log keeps out (main.tsx). */
+export function typedUrlKeys(): readonly string[] {
+  return ALL.flatMap((m) => m.typedUrlKeys ?? []);
+}
 export function foreignUrlKeys(page: Page): readonly string[] {
   return ALL.filter((m) => m.id !== page).flatMap((m) => m.urlKeys);
 }