feat(screenshots): cropped shots, sizes for the site, a site check

- shots.py crops to a region (clip) or to what one or more elements cover
  (element, pad), per-shot viewport; capture.py writes the published sizes to
  src/data/screenshots.json so the page reserves the right space.
- anonymize.py no longer empties secrets that netOrk compares with each other
  (Wi-Fi keys on an SSID against the key read from the access point). Emptying
  them invented passphrase "drift" that never existed; a keyed hash keeps equal
  equal, reverses nothing, and its key lives for one run.
- scripts/check/site.py checks the built site in both languages at four widths:
  sideways overflow, one h1, images with alt and size, console errors, requests
  to other origins, links to unknown routes, old-URL redirects, language
  detection, and word counts against the budgets.

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

.gitignore

@@ -12,3 +12,6 @@ deploy.env
 # Screenshot tooling: bytecode, and database dumps that hold production data
 __pycache__/
 *.dump
+
+# Output of scripts/check/site.py
+.check/