update-instructions

Read the changes introduced on the current branch, including BOTH: 1. Uncommitted workspace modifications (staged and unstaged) 2. Committed changes that are on the current HEAD but not yet in the default upstream branch (e.g. `origin/main`) Guidance: - First, capture uncommitted diffs (equivalent of `git diff` and `git diff --cached`). - Then, determine the merge base with the default branch (assume `origin/main` unless configured otherwise) using `git merge-base HEAD origin/main` and diff (`git diff <merge-base>...HEAD`) to include committed-but-unpushed work. After understanding all of these changes, read every instruction file under `.github/instructions` and assess whether any instruction is invalidated. If so, propose minimal, necessary wording updates. If no updates are needed, respond exactly with: `No updates needed`. Be concise and conservative: only suggest changes that are absolutely necessary.