feat(store): add PostgreSQL foundation [T-009]

deploy/postgres/002_bell.sql

@@ -0,0 +1,73 @@
+-- Bell owns Tenant/Site/quota truth. Run as the cluster administrator or a
+-- migration role that can SET ROLE to bell_app.
+
+CREATE SCHEMA IF NOT EXISTS bell AUTHORIZATION bell_app;
+ALTER SCHEMA bell OWNER TO bell_app;
+
+CREATE TABLE IF NOT EXISTS bell.schema_migrations (
+    version bigint PRIMARY KEY,
+    applied_at timestamptz NOT NULL DEFAULT clock_timestamp()
+);
+ALTER TABLE bell.schema_migrations OWNER TO bell_app;
+
+CREATE TABLE IF NOT EXISTS bell.sites (
+    tenant_id text NOT NULL,
+    id text NOT NULL,
+    name text NOT NULL,
+    max_video_channels smallint NOT NULL DEFAULT 16,
+    version bigint NOT NULL DEFAULT 1,
+    created_at timestamptz NOT NULL DEFAULT clock_timestamp(),
+    updated_at timestamptz NOT NULL DEFAULT clock_timestamp(),
+    deleted_at timestamptz,
+    PRIMARY KEY (tenant_id, id),
+    CONSTRAINT bell_sites_video_quota_range
+        CHECK (max_video_channels BETWEEN 1 AND 128),
+    CONSTRAINT bell_sites_version_positive CHECK (version >= 1),
+    CONSTRAINT bell_sites_identity_not_blank
+        CHECK (btrim(tenant_id) <> '' AND btrim(id) <> '' AND btrim(name) <> '')
+);
+ALTER TABLE bell.sites OWNER TO bell_app;
+
+CREATE OR REPLACE FUNCTION bell.bump_site_version()
+RETURNS trigger
+LANGUAGE plpgsql
+SECURITY INVOKER
+SET search_path = pg_catalog, bell
+AS $function$
+BEGIN
+    IF NEW.tenant_id IS DISTINCT FROM OLD.tenant_id OR NEW.id IS DISTINCT FROM OLD.id THEN
+        RAISE EXCEPTION 'Bell site identity is immutable';
+    END IF;
+    NEW.version := OLD.version + 1;
+    NEW.updated_at := clock_timestamp();
+    RETURN NEW;
+END
+$function$;
+ALTER FUNCTION bell.bump_site_version() OWNER TO bell_app;
+
+DROP TRIGGER IF EXISTS bell_sites_bump_version ON bell.sites;
+CREATE TRIGGER bell_sites_bump_version
+BEFORE UPDATE ON bell.sites
+FOR EACH ROW EXECUTE FUNCTION bell.bump_site_version();
+
+CREATE OR REPLACE VIEW bell.site_quota_v1 (
+    tenant_id,
+    site_id,
+    max_video_channels,
+    source_version,
+    source_updated_at
+) AS
+SELECT
+    site.tenant_id,
+    site.id,
+    site.max_video_channels,
+    site.version,
+    site.updated_at
+FROM bell.sites AS site
+WHERE site.deleted_at IS NULL;
+ALTER VIEW bell.site_quota_v1 OWNER TO bell_app;
+COMMENT ON VIEW bell.site_quota_v1 IS
+    'v1 read-only site video quota projection owned by Bell and consumed by Sense';
+
+INSERT INTO bell.schema_migrations(version) VALUES (1)
+ON CONFLICT (version) DO NOTHING;