Budget Pacing Monitor

Reads an in-flight campaign's spend against its intended target curve and returns a pacing verdict (On-track / Ahead / Behind / Stalled), the learning-phase status, an over/under-delivery call, and a reallocation trigger when the gap crosses a stated band. This is the in-flight S-lever watcher on the ROAS loop — distinct from budget-optimizer (which sets the initial allocation this skill monitors), bid-strategy-planner (which picks the bid strategy), and ad-account-auditor (which computes the RQS). It owns the spend curve, the pace read, and the reallocation trigger — not the number it started from and not the score.

Quick Start

Check pacing on Campaign X — daily budget is $200, we're 9 days into a 30-day flight. Am I on track?
Spend spiked on the prospecting set two days ago and the daily cap is getting hit by noon — over-delivering?
This campaign has spent 30% of budget with 60% of the flight gone — is it under-delivering, and should I move budget?

Skill Contract

Expected output: a pacing read for one campaign or flight — cumulative spend vs the target curve (percent-to-pace), a verdict (On-track / Ahead / Behind / Stalled), the learning-phase status, an over/under-delivery call with the driver (cap-limited, bid-throttled, low-volume, dayparting), and a reallocation trigger (fire / hold) with the band that decided it. Plus a handoff summary storable under memory/ad/budget-pacing-monitor/.