Cross-Platform Attribution Health Audit Attribution decay is the silent revenue killer of 2026 — Consent Mode V2 EEA enforcement (Jul 21, 2025), iOS ATT, SKAdNetwork → AdAttributionKit migration, and the death of third-party cookies have moved every advertiser's attribution signal toward modeled, server-side, first-party data. Misaligned attribution windows or unverified Consent Mode setups will mis-attribute 15-40% of conversions and silently waste budget. Process 1. Collect current attribution stack: GA4 property ID, Google Ads conversion actions, Meta CAPI config, Apple Ads / AdAttribution…