Wrap remaining gists endpoints (3 missing of 20)

[ldraney]

Parent Issue

#86 — Expand Octokit coverage

Category: gists

File: src/tools/categories/gists.ts
Current: 17/20

Already Wrapped

list, listPublic, listStarred, listForUser, get, create, update, delete, fork, star, unstar, checkIsStarred, listComments, getComment, createComment, updateComment, deleteComment

Methods to Add (3)

Method	Route
getRevision	GET /gists/{gist_id}/{sha}
listCommits	GET /gists/{gist_id}/commits
listForks	GET /gists/{gist_id}/forks

Pattern

See src/tools/categories/git.ts. Tool name: github_gists_<snake_case_method>.

Acceptance Criteria

• All 3 missing methods wrapped
• npm run build passes
• TOOLS.md updated