test: lock in pg/Kysely import isolation to database-postgres (E00-S03-T02)

- database-postgres-imports.test.mjs: static scan of every workspace package
  source proves pg/kysely import specifiers resolve only to
  packages/database-postgres; owner manifest pins the driver and no other
  package declares it; mutation probes prove the scan catches a driver import
  injected into apps/server/src/index.ts; comment-stripping and specifier
  matcher unit probes; CI-enforcement assertion
- workspace-layout / workspace-config / strict-tsconfig / typescript-pin:
  package-set fixtures updated to include packages/database-postgres
- docs/development/non-container.md: workspace package table and build
  expectations updated for the new package

tests/workspace-layout.test.mjs

@@ -38,6 +38,7 @@ const TOP_LEVEL_GROUPS = ['apps', 'packages', 'extensions'];
 const EXPECTED_PACKAGES = {
   '@personal-blog/server': 'apps/server',
   '@personal-blog/core': 'packages/core',
+  '@personal-blog/database-postgres': 'packages/database-postgres',
   '@personal-blog/example-extension': 'extensions/example',
 };