Cloud Agent dev environment setup (no repo changes)

[jackpope]

Summary

Sets up the Cursor Cloud Agent development environment for this React monorepo. Per follow-up request, the setup notes are not committed — AGENTS.md is kept as local, filesystem-loaded agent context (git-excluded) rather than added to the repo.

This branch has no net changes vs main (it added AGENTS.md, then stopped tracking it). It can be closed without merging; nothing needs to land in the repository. The environment itself is delivered via the Cloud Agent update script + base-image toolchain, not via repo files.

Environment setup performed

• Node v20.19.0 (pinned by .nvmrc) via nvm, made default for login shells through ~/.bashrc (the VM default /exec-daemon/node is v22). yarn@1.22.22 installed for node 20.
• Rust stable 1.98 via rustup (compiler crates/ need edition 2024 / resolver 3, i.e. ≥ 1.85; base image had 1.83).
• Dependencies (update script): root, compiler, compiler/apps/playground, and fixtures/dom yarn installs (--frozen-lockfile).

Verification

Area	Command	Result
React core — test	yarn test --no-watchman ReactCreateElement	pass
React core — Flow	yarn flow dom-node	No errors
React core — lint	yarn lint	Lint passed
React core — build	yarn build --r=experimental	built build/oss-experimental
Compiler — lint	yarn workspace babel-plugin-react-compiler lint	pass
Compiler — tests	yarn snap	1810/1810 passed
Rust port	cargo test (in compiler/)	all crates build + pass
Playground app	yarn dev (Next.js :3000)	compiled a component end-to-end
DOM fixture	yarn predev + yarn dev (CRA :3001)	rendered + controlled input verified

Where the notes live now

• Local, git-excluded /workspace/AGENTS.md (auto-loaded by Cursor from the filesystem; rides along in a saved environment snapshot).
• Durable backup in the agent store at /cursor/stores/self/AGENTS.md.
• Recommended for true "in Cursor, not in repo" persistence: paste into Cursor Rules/Memories.