feat: add --develop flag to taskgraph load-task

[ahal]

This flag will setup the current local checkout as a volume to the task's checkout and avoid all VCS operations.

This allows developers to make changes to the source and immediately see it in action in the task.

[jcristau]

I worry a bit that tasks might treat the checkout as throw-away, and the risk of losing data; but the warning in the doc might be good enough, and the only thing I know for sure can trash the repo is robustcheckout, and AIUI that is bypassed here.

One other thing that might cause issues is permissions, since the host and in-docker UIDs can easily not match.

[ahal]

I worry a bit that tasks might treat the checkout as throw-away, and the risk of losing data; but the warning in the doc might be good enough, and the only thing I know for sure can trash the repo is robustcheckout, and AIUI that is bypassed here.

One other thing that might cause issues is permissions, since the host and in-docker UIDs can easily not match.

Yeah, anecdotally I've hit permission issues already. I'm not sure there's really a good solution for this. Regarding dataloss potential, yeah that's a bit riskier. We could maybe put up a warning prompt the user has to by-pass before proceeding? Though part of my motivation for this was to get Claude to fix task failures in the background, so I'd like to make sure it can still be used without any interaction.

[ahal]

Added a warning prompt the user needs to bypass. Can be disabled by setting an env.