- Intelligent bun/node detection based on package manager context
- Respects engines.bun field for runtime preferences
- Conservative defaults: only uses bun when explicitly requested
- Automatic shebang replacement with shell script wrapper

- Graceful CJS fallback when TLA is detected
- Automatic CJS generation disabling with helpful user messaging
- Proper package.json generation for ESM-only modules

- Single-batch ESM build for src/ and bin/ entries
- Smart externalization: entry points externalized, nested files bundled
- Improved build performance with unified build graph

- Fix TypeScript declaration generation for bin entries
- Fix CLI argument parsing for directory paths with npm flags
- Make TypeScript declarations conditional on tsc availability

- 112 tests passing
- Comprehensive test coverage for all new features
- Tests for dual runtime, TLA, and externalization logic