Replace RFC 7489 PSL-based org-domain lookup and RFC 9091 PSD DMARC
fallback with the DMARCbis DNS Tree Walk algorithm (max 8 queries,
8-label shortcut, TLD records require psd=y). Add parsing for the new
t= (test mode), psd= (y/n/u), and deprecated tag detection (pct, rf,
ri). Update validateDMARC to accept p=-absent records with rua= per
DMARCbis §4.7. Score t=y by downgrading effective policy one level.
Surface user-facing advisories in DmarcRecordDisplay: deprecation
warnings for pct=/rf=/ri=, test mode explanation with per-policy
impact, and PSD/org-domain boundary notices.
Pierre-Olivier Mercier
809bca02e4