feat: PostgreSQL driver support

docs/development.md

@@ -56,6 +56,7 @@ If your editor reports `pattern all:dist: no matching files found`, either run `
 task --list          # everything available
 task test            # Go tests; extra args pass through: task test -- -run TestCreateArticle -v
 task test:mysql      # MySQL tests against real servers in Docker (mysql:8.4, then mariadb:11)
+task test:postgres   # PostgreSQL tests against real servers in Docker (postgres:16, then postgres:17)
 task cover           # coverage of the use cases → tmp/coverage.out
 task mutate          # gremlins mutation testing → tmp/gremlins.json
 task test:web        # SPA component tests (Vitest)