feat(F-002): database foundation with migrations and dev compose

- node-pg-migrate + pg: baseline migration (extensions, app_meta) with working down
- src/infrastructure/db fail-fast pool and typed query helper
- docker-compose: postgres:16-alpine + redis:7-alpine with one-command up
- table naming convention <module>_<table> documented in README
- integration tests (6) against real PostgreSQL; strict identifier validation
  for test DDL after security-gate hardening round
- deps justified in spec/tech.md; all gates approved; verify.sh green

project/vitest.config.ts

@@ -3,7 +3,9 @@ import { defineConfig } from 'vitest/config';
 export default defineConfig({
   test: {
     environment: 'node',
-    include: ['src/**/*.test.ts', 'scripts/tests/**/*.test.ts'],
+    // Integration tests recreate a shared test database; parallel files would race.
+    fileParallelism: false,
+    include: ['src/**/*.test.ts', 'src/**/*.itest.ts', 'scripts/tests/**/*.test.ts'],
     exclude: ['node_modules/**', 'dist/**', 'scripts/tests/fixtures/**'],
   },
 });