feat(layouts): switch track layout mid-practice and view stats per layout

A club can run one Open Practice all season and re-lay the track now and then.
Previously a session's layout was frozen at start and every training lap inherited
it, so a season-long practice stayed on its first layout forever, and changing layout
was hidden under Settings -> Appearance.

- Each practice lap now counts toward the layout active when it was driven; a running
  practice session moves onto a new layout when one is added
- "New layout" strip on Training stats, Race Day and the Dashboard, offered only around
  practice; a running race session blocks layout changes everywhere
- "Stats for" selector (current / older layout / before layouts / all layouts) on
  Training stats and in the driver's mobile profile (?layout= on the public API)
- A layout that has practice laps on it can no longer be deleted
- Fix: the buildDriverTrainingStats wrapper in app.js dropped extra arguments

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/browser_smoke.js

@@ -9,6 +9,7 @@ import { runSettingsTabsSmoke } from "./browser_settings_tabs.js";
 import { runGuideTabsSmoke } from "./browser_guide_tabs.js";
 import { runAuthSmoke } from "./browser_auth.js";
 import { runTtsSettingsSmoke } from "./browser_tts_settings.js";
+import { runTrackLayoutsSmoke } from "./browser_track_layouts.js";
 import { runObsPopupSmoke } from "./browser_obs_popup.js";
 import { runDecoderReconnectSmoke } from "./browser_decoder_reconnect.js";
 import assert from "node:assert/strict";
@@ -148,6 +149,7 @@ try {
   await runGuideTabsSmoke({ evaluate, navigate });
   await runAuthSmoke({ evaluate, navigate, fill, savedState, waitFor });
   await runTtsSettingsSmoke({ evaluate, navigate, savedState, waitFor });
+  await runTrackLayoutsSmoke({ evaluate, navigate, savedState, waitFor, base, dialogs });
   await runRaceDaySmoke({ evaluate, navigate, fill, savedState, waitFor, pause, base, dialogs });
   await runRaceDayStartSequencesSmoke({ evaluate, navigate, waitFor, pause, base, dialogs });
   await runObsPopupSmoke({ evaluate, navigate, fill, savedState, waitFor, pause, base, debugPort, dialogs, realClick });