setup-knowledgebaselisted

Set up the knowledgebase structure in the current repository. Idempotent: never overwrite anything that already exists; if `.knowledgebase/` is already there, report what is present and only fill gaps. 1. Find the repo root: `git rev-parse --show-toplevel`, or the current directory outside git. 2. Create `.knowledgebase/entries/`. 3. Ask whether the base is shared (git-tracked, the default) or local-only. Local-only fits repos where you cannot commit your own folder, such as client repos: append `.knowledgebase/` to `.gitignore` and write `git=ignored` into `.knowledgebase/config`. The base then never rides commits; review happens through the session-end report and the `/browse` page, and agents can never write `decided-by: human` or `verified-by: human` there. 4. Propose a scope vocabulary and write it to `.knowledgebase/scopes`, one lowercase word per line. Derive candidates from the repo itself: top-level source directories, service names in compose files, package manifests. Aim for 4 to 8 scopes; always include `core`. Show the proposed list to the user and let them curate it. Fewer, broader scopes beat many synonyms. 5. Write `.knowledgebase/CONTRACT.md` from [kb-contract-template.md](kb-contract-template.md), verbatim. 6. Append the agent manual from [claude-md-section.md](claude-md-section.md) to the repo's `CLAUDE.md`, and to `AGENTS.md` if the repo has one, verbatim. Skip any file that already contains a `## Knowledgebase` heading. If neither file exists, creat