Bun has unfixed segfault issues on Windows when spawning subprocesses
(oven-sh/bun#25798, #26026, #23043). Even upgrading to Bun v1.3.6+
does not resolve the crashes.
Instead of blocking LSP on Windows with version checks, use Node.js
child_process.spawn as fallback. This allows LSP to work on Windows
regardless of Bun version.
Changes:
- Add UnifiedProcess interface bridging Bun Subprocess and Node ChildProcess
- Use Node.js spawn on Windows, Bun spawn on other platforms
- Add CWD validation before spawn to prevent libuv null dereference
- Add binary existence pre-check on Windows with helpful error messages
- Enable shell: true for Node spawn on Windows for .cmd/.bat resolution
- Remove ineffective Bun version blocking (v1.3.5 check)
- Add tests for CWD validation and start() error handling
Closes#1047
Ref: oven-sh/bun#25798
