Apply ai-env Template

Apply the agentic development environment template to the current repository.

Argument: optional path to ai-env clone. No argument = clone from GitHub (primary path).

Phase 0 — Pre-flight

Clean working tree check

Run git status --porcelain. If there are uncommitted changes, warn the user and ask whether to proceed or stash first. A dirty tree makes it hard to review what the template changed.

Phase 1 — Source Resolution & Discovery