fix(scanner): reliable cookie discovery, auto-categorisation, and scan scheduling UI (#7)

Scanner fixes:
- Remove conflicting ``path`` from consent pre-seed cookie (Playwright
  rejects cookies with both ``url`` and ``path``).
- Switch to ``networkidle`` + 5s + 2s delayed second-pass for reliable
  cookie capture.
- Check sitemap Content-Type to skip SPA HTML fallbacks.
- Propagate ``auto_category`` from scan results to the cookies table
  during sync (was silently dropped).
- Add ``_gcl_ls`` to the Open Cookie Database CSV.
- Classify ``_consentos_*`` cookies as necessary directly in the
  classification engine.
- Add ``seed_known_cookies`` to the bootstrap init container command.

Admin UI:
- Add scan schedule control to the Scans tab — preset options
  (disabled/daily/weekly/fortnightly/monthly) plus custom cron input.
  Saves ``scan_schedule_cron`` on the site config.

apps/api/data/open-cookie-database.csv

@@ -2263,3 +2263,4 @@ c7d8e9f0-0012-4567-890a-000000000012,Plausible Analytics,Analytics,plausible_,,"
 c7d8e9f0-0013-4567-890a-000000000013,Fathom Analytics,Analytics,_fathom,,"Privacy-focused simple website analytics with minimal data collection.",Varies,Conva Ventures Inc,https://usefathom.com/privacy,1
 c7d8e9f0-0014-4567-890a-000000000014,Umami,Analytics,umami.,,"Open-source privacy-friendly web analytics alternative.",Varies,Website operator,https://umami.is/docs/about,1
 c7d8e9f0-0015-4567-890a-000000000015,Vercel,Functional,_vercel_,,"Vercel platform cookies for deployment previews and analytics.",Varies,Vercel Inc,https://vercel.com/legal/privacy-policy,1
+c7d8e9f0-0016-4567-890a-000000000016,Google Ads,Marketing,_gcl_ls,,"Google Click Identifier for localStorage-based ad conversion tracking.",90 Days,Google,https://business.safety.google/privacy/,0