Add a `milestone` argument to `create_issue` and `update_issue` accepting
either a numeric milestone id or a title (resolved case-insensitively against
open and closed milestones, with a clear error for unknown titles). On
`update_issue`, `milestone: 0` clears the milestone. A BeforeValidator rejects
booleans so they are not silently coerced to an id.
Gitea Projects (Kanban boards) were investigated for #22 and are intentionally
left unsupported: Gitea 1.26.2 exposes no project endpoints in its REST API.
Documented this in api-reference.md and refreshed the (stale) write-mode tool
list to cover all 16 write tools.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>