RootGauge_RootPool: three deployed root gauges have no leaf mapping (latent data drop)

[FonsSicca]

Source: data-quality audit of deployment 8fcf9a8 (2026-07-07). Full findings: Notion audit.

What to build

Map the three deployed root gauges that currently have no RootGauge_RootPool leaf mapping and no pending row. There is zero traffic through them so far, so nothing is miscounted today, but the first event through any of them would drop. This is a latent data-loss trap waiting on traffic.

Acceptance criteria

• The three root gauges are mapped, or a pending-row path captures the first event so nothing drops.
• Test covers an event arriving on a previously-unmapped root gauge.

Blocked by

None — can start immediately.