Replace Bun-specific file operations with Filesystem module: - Add Filesystem import from ../util/filesystem - Replace Bun.file().exists() with Filesystem.exists() - Replace Bun.write() with Filesystem.write() All 17 skill tests pass.
Replace Bun-specific file operations with Filesystem module: - Add Filesystem import from ../util/filesystem - Replace Bun.file().exists() with Filesystem.exists() - Replace Bun.write() with Filesystem.write() All 17 skill tests pass.