Records the grill-with-docs outcomes for the ara_first_run rebuild: three
composable stage orchestrators (Ingestion/Baseline/Modelling), one lambda per
use case chaining them through repos (not in-memory), and the Fetcher-vs-Repo
data-source taxonomy. Amends ADR-0003's chaining rule to generalise beyond
RefreshOrchestrator. Adds the pipeline-composition + First Run vocabulary to
CONTEXT.md.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>