chore: bump version to v2026.4.337 and update changelog}
- Bump package version from 2026.4.336 to 2026.4.337
- Update p3x-redis-ui-material dependency from ^2026.4.332 to ^2026.4.333
- Add key export/import feature documentation to README (JSON export with TTL preservation, import with virtual scroll preview and conflict handling)
- Add v2026.4.337 changelog entry
- Update build version footer across all documentation and changelog files
- Add .changelog-prompt.tmp for Claude-based changelog generation