RFCs

Substantial design changes go through an RFC so the discussion is recorded next to the code.

1. Copy the RFC template to NNNN-short-title.md with the next free number.
2. Open a PR. Discussion happens on the PR.
3. When accepted, the PR merges and a matching entry is added to docs/decisions/.

What needs an RFC: anything in the “Open questions” section of the architecture document, new protocols or wire formats, changes to the approval tiers, changes to the slash prefix grammar, adding a backend.

What does not: bug fixes, implementation of an already-decided design, docs.