Replace Bun shell template literals (ctx.$) with node:child_process.spawn to work around Bun's ShellInterpreter garbage collection bug on Windows. This bug causes segmentation faults in deinitFromFinalizer during heap sweeping when shell operations are used repeatedly over time. Bug references: - oven-sh/bun#23177 (closed incomplete) - oven-sh/bun#24368 (still open) - Pending fix: oven-sh/bun#24093 The fix applies to all platforms for consistency and safety.