test(architecture): guard top-level timers + add startup-contract smoke test

Add a tiny source-level architecture suite at
tests/test-architecture-startup-contracts.el with two checks:

- Only keybindings.el may globally own the exact C-; prefix.  Catches
  accidental cross-module rebinding before it ships.
- Top-level timer scheduling (run-with-timer / run-at-time /
  run-with-idle-timer) must be guarded by (unless noninteractive ...)
  so requiring a module in batch / test mode does not schedule
  startup timers.  Timer calls inside defuns are exempt -- the test
  only rejects forms that execute their body when the module loads.

Four modules had unguarded top-level timer scheduling and would have
tripped the new test.  Wrap their startup hooks/timers in
(unless noninteractive ...):

- modules/org-agenda-config.el: 10s idle cache build
- modules/org-refile-config.el: 5s idle cache build
- modules/quick-video-capture.el: after-init-hook + 2s fallback
- modules/wrap-up.el: emacs-startup-hook bury-buffers delay

The contract being protected is "requiring a module in batch should
not start a clock running."  Test failures will now point straight at
the offending file/form.

1 files changed, 2 insertions, 1 deletions

diff --git a/modules/wrap-up.el b/modules/wrap-up.el
index 523d55b2..93b74776 100644
--- a/modules/wrap-up.el
+++ b/modules/wrap-up.el
@@ -25,7 +25,8 @@
 (defun cj/bury-buffers-after-delay ()
   "Run cj/bury-buffers after a delay."
   (run-with-timer 1 nil 'cj/bury-buffers))
-(add-hook 'emacs-startup-hook 'cj/bury-buffers-after-delay)
+(unless noninteractive
+  (add-hook 'emacs-startup-hook 'cj/bury-buffers-after-delay))
 
 (cj/log-silently "<-- end of init file.")