Reference Implementation Architecture

ADDED Requirements

Requirement: Store-Parity Spine Source Run Summary Index

The reference implementation SHALL provision equivalent SQLite and Postgres spine_events index coverage for source-filtered run-summary aggregation.

Scenario: Fresh stores provision equivalent summary coverage

WHEN a fresh SQLite or Postgres reference store is initialized THEN the store SHALL include a source/run summary index over source_kind, source_id, run_id, and descending occurred_at AND the index SHALL exclude rows without run_id.

Scenario: Existing stores converge without result changes

WHEN an existing SQLite or Postgres reference store runs schema initialization again THEN the store SHALL create the source/run summary index if it is missing AND the migration SHALL NOT rewrite spine_events rows or change query results.