chore: source formatting and spec allignment

crates/bds-core/migrations/V3__align_ai_schema.sql

@@ -0,0 +1,5 @@
+ALTER TABLE chat_messages ADD COLUMN cache_read_tokens INTEGER;
+ALTER TABLE chat_messages ADD COLUMN cache_write_tokens INTEGER;
+
+ALTER TABLE ai_providers RENAME COLUMN npm TO package_ref;
+ALTER TABLE ai_models RENAME COLUMN provider_npm TO provider_package_ref;