The frozen shared substrate for every vgi-azure-* worker: the (tenant, client, audience) token cache, verbatim delta/nextLink paging, the canonical
clampWatermark(maxSeen, lagMs, now), 429/Retry-After backoff, the authenticated
fetch layer, and the _row_kind='marker' scan-state contract. Pure and edge-safe
(token minting is injected). Spec: vgi-tasker/vgi-azure-graph-core-SPEC.md.
bun install && bun test