Replace the hand-copied search_url (URL type) with a proper relation:
- watch: LinkToAnotherRecord (belongs-to, many keywords -> one Settings row),
picked from a dropdown in the UI so a wrong URL can't silently disable a keyword
- search_url: Lookup column that auto-fills Settings.url through the link
_ensure_keyword_watch_link() builds both columns idempotently on bootstrap and
upgrades a legacy URL-typed search_url to Link+Lookup. load_ignored_keywords()
now normalises Lookup values (string or array).
Silence Telegram alerts for listings whose title contains a keyword
configured for that watch, matched case-insensitively as a substring.
- New IgnoredKeywords table: search_url (watch key) + keyword (one per row)
- load_ignored_keywords() returns {search_url: {lowercase keywords}}, reloaded
every notification cycle so UI edits apply immediately
- title_matches_keyword() does the case-insensitive substring check
- send_pending_notifications() now also pulls search_url on pending records;
skip_notify=true + notified=true on a hit (still archived, no Telegram)
- Docs updated: AGENTS.md, README.md, DOCUMENTATION.md
hoelee