chore: clean up repo and fix docker compose configuration

- Remove outdated docs (COMPOSE.md, DOCKER.md, QUICKSTART.md, REBUILD_GUIDE.md)
- Remove build.sh, compose.production.yml, gamification-schema.sql, directus.yaml
- Simplify compose.yml for local dev (remove env var indirection)
- Add directus.yml schema snapshot and schema.sql from VPS
- Add schema:export and schema:import scripts to package.json
- Ignore .env files (vars set via compose environment)

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

.gitignore

@@ -3,5 +3,8 @@ dist/
 target/
 pkg/
 
+.env
 .env.*
 
+
+.claude/