fix: add --force flag to uv cache clean to prevent deadlock

[bkrabach]

Summary

• Fix amplifier reset hanging indefinitely when cleaning UV cache
• Add --force flag to uv cache clean command to bypass exclusive lock check
• Add 60-second timeout as a safeguard against future hangs

Problem

The amplifier reset command was hanging indefinitely while cleaning the UV cache. The root cause:

1. uv cache clean without --force waits for an exclusive lock on the cache directory
2. Since amplifier itself runs as a uv-installed tool, the cache is always "in use" when running amplifier reset
3. This creates an unresolvable deadlock - uv waits for the lock that can never be released

Solution

Per uv's documentation, the --force flag bypasses the in-use check. This is the intended solution for this scenario.

Additional safeguards added:

• 60-second timeout to prevent any future indefinite hangs
• Proper handling of subprocess.TimeoutExpired exception
• Updated docstring explaining why --force is required

Test plan

• Verified amplifier reset no longer hangs
• Tested with --dry-run flag shows correct command
• Confirmed cache is properly cleaned when running amplifier reset

🤖 Generated with Amplifier