-- Triggered on first start only (when $PGDATA is empty).
-- Enables TimescaleDB extension in the datahub database.
--
-- Three-layer defense for extension activation:
--   1. Upstream timescale image: /docker-entrypoint-initdb.d/000_install_timescaledb.sh
--      already runs CREATE EXTENSION in $POSTGRES_DB; this file is defensive backup.
--   2. This script: explicit \connect datahub then CREATE EXTENSION.
--   3. backend/migrations/2026_05_07_100000_enable_timescaledb_extension.php
--      runs CREATE EXTENSION IF NOT EXISTS on application boot.
--
-- All three layers are idempotent (IF NOT EXISTS), zero runtime cost.

\connect datahub

CREATE EXTENSION IF NOT EXISTS timescaledb;

-- Future extensions can be added here, e.g.:
-- CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
-- CREATE EXTENSION IF NOT EXISTS pg_trgm;