[Bug] Bundle preparation fails on Windows: uv pip install -e cannot overwrite running amplifier.exe (OS error 32)

Description

amplifier run fails on Windows because bundle preparation calls uv pip install -e on every invocation, which attempts to remove/overwrite the currently running amplifier.exe. Windows file locking prevents this.

Environment

• OS: Windows 11 (10.0.26200) ARM64
• Python: 3.13.12
• amplifier: 2026.02.14-a94f815
• uv: installed via pipx
• Install method: editable (pip install -e .)

Reproduction

amplifier run --mode single "What is 7 * 8?"

Error

Preparing bundle 'foundation'...
Failed to install module from C:\Users\<user>\.amplifier\cache\amplifier-d1dda27a16518560.
stderr: error: failed to remove file `...\Scripts\amplifier.exe`:
  The process cannot access the file because it is being used by another process. (os error 32)

Notes

• Same command works on WSL/Linux — Unix allows deleting a running binary, Windows does not.
• The error originates in amplifier-foundation/modules/activator.py → _install_dependencies().

Start in amplifier-foundation/modules/activator.py at _install_dependencies(), then reproduce amplifier run --mode single "What is 7 * 8?" on Windows. Done means bundle preparation no longer tries to overwrite the running amplifier.exe and the command succeeds, while the existing Linux behavior remains working.