Production hardening (2026-07 multi-agent audit, 25 confirmed findings
fixed) + backward-compat-lifted API cleanup. Breaking: AdBlocked(reason)
AdLoadState case, widget-first AdFlowBanner/AdFlowNativeAd, show() reward
callback only on rewarded formats, AdGate.canShow removed, showOnColdStart
removed. Added: runtime SSV, mediation observability (AdResponseSummary,
paid-event slot/adSourceName), maxAdAge expiry, live canRequestAds,
config validation, drop-on-Remove-Ads/consent-withdrawal.

Validated on Android emulator + iOS simulator with Google test IDs.
See CHANGELOG.md and MIGRATION.md.