docs(readme): state that fork main is not the working base

[Fl0p]

What

Adds an About this fork section at the top of the README on the fork's default branch.

It says three things:

• this fork exists to prepare PRs for ChiR24/Unreal_mcp, not as a distribution;
• upstream main (and therefore this fork's main) has been dormant since June 2026, is 700+ commits behind dev, and shares no common ancestor with it - fixes that exist on dev still reproduce on branches cut from main;
• real work happens on base/upstream-dev-* snapshots, linking the existing Fork CI: review bases doc.

Why

Both known defects handled in this fork (bare remove_variable/rename_variable returning UNKNOWN_ACTION, and posX/posY ignored in create_node) are fixed only in upstream/dev and still reproduce on the default branch here. An outside reporter already hit that trap. The README was the cheapest reversible fix - the default branch is deliberately left alone.

Scope

Docs-only: one section, 21 added lines in README.md. No workflow, code, or branch-setting changes.

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: e2601b09-4b5a-48fa-a544-664dd168b83c

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}