README.md is a front door under 60 KB: what the forge is, how to run it, and a linked index into docs/ #6226

README.md is 2,014 lines and 211 KB. A person reading the forge's story meets the crew, origins and apps internals before they see how to use it, and every files page drew all of it until the tree page was cut.

Done when:

• [ ] README.md keeps its opening, "Run it", "On your machine", "Develop" and "What works today", and ends with an index that links to every docs/ file it hands off to.
• [ ] "The crew" moves to docs/CREW.md, "Origins" to docs/ORIGINS.md and "Apps" to docs/APPS.md. Each file is merged into what is already there, with nothing lost and no duplication.
• [ ] README.md is under 60 KB.
• [ ] The tests that read README.md (e.g. test/feeds.test.ts, test/lands-once.test.ts, test/crew-app-hosts.test.ts) read the file the text now lives in, and they all pass.

Files: README.md, docs/CREW.md, docs/ORIGINS.md, docs/APPS.md, the tests that read README.md. Risk: a test grepping README for a phrase. Run grep -rl README.md test first.