chore(skills): add the rfc-issue skill

.claude/skills/rfc-issue/SKILL.md

@@ -0,0 +1,113 @@
+---
+name: rfc-issue
+description: Write the tracking issue for an RFC — a short Description / Motivation / Requirements / Tasks body labeled `rfc`, written either from an RFC document already in review or from notes when no RFC exists yet. Use for "open a tracking issue for this RFC", "create issues for the open RFCs", or when an idea needs an RFC that nobody has drafted.
+argument-hint: [RFC PR number, RFC path, or a description of the idea]
+---
+
+# RFC tracking issue
+
+One issue per RFC. The document carries the specification and its review; the issue
+carries the work — landing the document, then implementing it in rust-core and in each
+host. They stay separate because a merged RFC is not a shipped RFC, and the PR closes
+long before the hosts catch up.
+
+## Shape
+
+**Title** — `RFC: <Title>`, with the RFC number dropped. `RFC 0025: Credential-endpoint
+remote permission` becomes `RFC: Credential-endpoint remote permission`. The number
+belongs to the document: it changes when the document is renumbered and it collides
+between RFCs in flight.
+
+**Label** — `rfc`.
+
+**Body** — four sections, nothing else:
+
+```markdown
+**Source PR:** #<pr> · `docs/rfcs/<file>.md` · @<author>
+
+## Description
+
+One or two sentences: what the protocol does once this lands.
+
+## Motivation
+
+One or two sentences: the gap that exists without it.
+
+## Requirements
+
+- Three to five one-line bullets: the load-bearing constraints an implementer
+  cannot get wrong.
+
+## Tasks
+
+- [ ] RFC document body
+- [ ] Implementation — rust-core
+- [ ] Implementation — hosts
+  - [ ] dotli
+  - [ ] Desktop
+  - [ ] iOS
+  - [ ] Android
+  - [ ] host-cli
+```
+
+## Writing each section
+
+**Source line.** `#<pr>` is the whole linking mechanism — GitHub autolinks it and writes
+a cross-reference into the PR's timeline, so the two connect in both directions with no
+comment on the PR.
+
+**Description.** What the system *does* once this lands: "the manifest defines four
+executable types", never "this PR adds a fourth type". The issue outlives the PR, and
+after a squash-merge the transition wording is noise.
+
+**Motivation.** The gap, stated concretely enough that someone can disagree with it.
+"Products cannot tell which host is running them" beats "improves observability".
+
+**Requirements.** The handful of things an implementer cannot get wrong — a wire-level
+constraint, an ordering rule, a security property, a normative MUST. Not a précis of
+Detailed Design. If a bullet needs a second line to survive, it belongs in the document,
+not here.
+
+**Tasks.** Fixed. Five host boxes stay in every issue even where a host plainly will not
+implement this one: a missing box reads as done, an unchecked box reads as outstanding,
+and only one of those is true.
+
+An open problem with the document itself — a colliding RFC number, a `00XX` placeholder
+filename — goes in one italic `_Note:_` line after Tasks. Nothing else is appended.
+
+## When no RFC PR exists
+
+The issue often comes first: a gap surfaces in review of something else, or the user
+describes a change nobody has drafted. Write the same four sections, sourced from the
+conversation and the code rather than from a document, and change two things:
+
+- Replace the source line with where the idea came from — `**Raised in:** #444
+  (review)`, `**Design doc:** docs/design/<file>.md`, or `**Source:** discussion with
+  @handle`. Never invent a `docs/rfcs/` path for a file that does not exist.
+- Say so, so nobody looks for the document: `_Note: no RFC drafted yet._`
+
+Requirements are the part that goes thin here, and that is honest — write the
+constraints that are actually settled and leave the rest to the RFC. A requirement
+invented to fill the section will be read as a decision someone made.
+
+Then hand off: the `rfc` skill drafts the document, and this issue is the notes it
+interviews against. The `RFC document body` box is what tracks that gap.
+
+## Before opening anything
+
+Sixteen issues land in everyone's notifications at once. Draft the bodies, show them,
+and get a yes before the first `gh issue create`.
+
+Check for an existing issue first. Two PRs against one document are still one document:
+an RFC amending `product-manifest.md` gets its own issue, but a second PR against the
+same amendment does not.
+
+```bash
+gh issue list --label rfc --state all --limit 100
+gh issue create --title "RFC: <Title>" --body-file <path> --label rfc
+```
+
+## Related
+
+`.claude/skills/rfc/SKILL.md` writes the document itself. That skill ends at the
+document; this one covers the issue on either side of it.