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/lib/moduleDef.ts

@@ -50,6 +50,10 @@ export type ModuleDef = {
   // along onto another's URL. Empty for a page with nothing of its own in the URL. Each key belongs to
   // one module and none is a shell key (moduleUrl.contract.test).
   urlKeys: readonly string[];
+  // Those of them that carry what the user TYPED (a search box's text): the client log keeps their
+  // values out below its most detailed level, as it does the shell's own (lib/logHooks). A new search
+  // box's key is declared here with it (moduleUrl.contract.test holds them to urlKeys).
+  typedUrlKeys?: readonly string[];
   // Its page plays YouTube videos in the player and reopens it from an address that names one (a
   // reload, a bookmark — lib/playerUrlState), with its own list as the queue. A page without it gets
   // the shell's player for such an address: the video alone.