Two frontend layouts, each laid out on disk inside its own application's
configure(). The harness runs that lazily at first access, so @TempDir is
populated by then and the server for whichever test is not running never boots.
Replaces three blocks of HttpRequest.newBuilder(URI.create(...)) per test with
single-line assertions. 98 to 60 code lines.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>