For agents, on top of README.md, which they read first.

• execution.bzl is kept identical across the estate's buck2 repositories on purpose; change it everywhere or nowhere (its header says so).
• The repository must build with the flag false. Never make anything here read a credential, require the cache, or default [buildbuddy] cache to true: a clone without the user-level buckconfig has to get exactly the prelude's local-only platform.
• Cache-only, not remote execution. remote_enabled stays False; the build depends on the devshell's tools on this host (PATH-based toolchains, chapter 29), which a remote worker would not have.