feat: commit built database for reliable deployment

Database is a build artifact but committed for repos with
rate-limited or hard-to-extract data sources. Rebuild with:
npm run build:db

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -1,6 +1,5 @@
 node_modules/
 dist/
-*.db
 data/source/
 !data/.gitkeep
 .env