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/modules/settings/SettingsPanel.tsx

@@ -26,7 +26,7 @@ import { api, HttpError, type Me } from "../../lib/api";
 import { displayName, roleKey } from "../../lib/api/account";
 import { notifyActionError } from "../../lib/actionErrors";
 import { LS, useTabPersistedState } from "../../lib/storage";
-import { SETTINGS_TAB_KEY } from "../../lib/settingsTab";
+import { SETTINGS_TAB_KEY, settingsTabParams } from "../../lib/settingsTab";
 import { useUrlMirror } from "../../lib/useUrlMirror";
 import Avatar from "../../components/ui/Avatar";
 import { notify, type NotifSettings } from "../../lib/notifications";
@@ -80,7 +80,7 @@ export default function SettingsPanel() {
     : "appearance";
   // The address names the tab on screen, so a bookmark opens it (always written: without it, the page
   // opens on the tab this browser tab last showed).
-  useUrlMirror({ [SETTINGS_TAB_KEY]: tab });
+  useUrlMirror(settingsTabParams(tab));
 
   return (
     <div className="p-4 max-w-3xl w-full mx-auto">