PARTIAL SAVE: writes ONLY the 'Attribution' field of TitlePublicConfigurationModel; all other v1/v2 fields stay untouched. Acquisition attribution — how the engine records WHERE a player came from. The signal (utm_source/medium/campaign/term/content, the ad network's click id, the referrer, the invite code) arrives with the login request and is stored as a chain of touch points on the player: the first touch is immutable, the last touch tracks win-backs, and the chain in between feeds multi-touch models. This section only tunes that recording: how many touches to keep, how long after a touch an identical signal is still considered the same click rather than a new one, and optional aliases that normalise messy source/medium values into canonical ones for analytics. Referral invites are recorded through this same mechanism as a channel, so they show up in the acquisition reports alongside paid traffic.