Clean up stale branches without the guesswork

**Objective:** Audit branches and tags in `{repository-name}` and list cleanup candidates: branches with no commits for `{stale-days}` days (default 90), locked refs and far-diverged branches.

**Step 1: Resolve the repository**

Call `azure-devops-get-repository` with name `{repository-name}`; note id and default-branch.

**Step 2: Read branches**

Call `azure-devops-get-branch-stat` with repository-id and commit-date.to set to the stale cutoff. Also call `azure-devops-get-git-ref` with repository-id and `azure-devops-get-tag` for context, noting is-locked refs and the creator.

**Step 3: Rank candidates**

Rank by days since last commit, then by ahead-count. A branch with ahead-count 0 is likely already merged.

**Step 4: Report**

A table of branch, last commit date, author, ahead and behind counts and a suggested action (delete, ask owner, keep), plus counts for locked refs and tags.

**Rules & Guidelines:**

* This prompt is read-only. Call only the `azure-devops-get-*` read tools named above; never create, update, comment on, approve, queue, abort or delete anything in Azure DevOps.
* The tools only return data the connected account can see; never infer data from projects outside that access.
* Never delete or lock branches; list candidates only.
* Never suggest deleting the default branch or any branch behind a pull request that is still active.

**Validation:**

* If no branches are stale, say so.