sketch -unsafe without -git-remote-addr doesn't notify about new commits

[philz]

	sketch, err := resolveRef(ctx, repoRoot, "sketch-wip")

Ever since we switched to making the agent use sketch-wip, we only notify the user on new commits when sketch-wip is updated rather than HEAD. In unsafe, if you don't set a git-remote-addr and friends, Sketch just works in your current branch, and therefore we don't notice changes.

The configuration space is gnarly here. We should notify but not push, probably.