test(config-utilities): cover with-timer, compile-buffer, summary, info commands

Four new test files extending the existing coverage of
cj/emacs-build--format-build-time. The interactive heavyweights
(cj/recompile-emacs-home, cj/delete-emacs-home-compiled-files,
cj/benchmark-this-method, cj/validate-org-agenda-timestamps) are out
of scope for this pass — each needs an internal/wrapper split first
before tests can exercise the logic without UI.

- with-timer macro: 4 tests asserting it returns the FORMS' value,
  evaluates the body exactly once, emits both announce and done
  messages, and returns the last form when given multiple.
- cj/compile-this-elisp-buffer: 6 tests dispatching across native-async,
  native-sync, and byte-compile fallbacks, plus the not-elisp /
  no-buffer-file-name error paths and the sync-native error catch.
- cj/emacs-build--summary-string: 5 tests asserting the shape of the
  multi-line report (Version, System, Build date, Capabilities section,
  yes/no flag rendering) without locking exact wording.
- info-commands smoke: 5 tests exercising cj/info-emacs-build,
  cj/info-loaded-packages, cj/info-loaded-features, cj/reload-init-file,
  and cj/org-alert-list-timers via boundary-mocked pop-to-buffer and
  load-file, asserting buffer creation, content shape, or echo-area
  message as appropriate.

20 new tests, all passing. Full suite green.

0 files changed, 0 insertions, 0 deletions