Establish working-draft RFC process and public Open RFCs list

Problem

APRF documents an RFC process in stewardship, but adopters could not see any live RFCs. Without a public Open RFCs list, stewardship looks inactive and “working draft” claims lack a visible change path.

Proposal

1. Publish this editorial RFC as APRF-RFC-0001 under `in-review` with the standard 14-day window.

2. Ship a machine-readable RFC index (`APRF_RFCS`) and render Open RFCs on `/aprf/rfc/`.

3. Keep APRF-RFC-0000 as the submission template.

4. No changes to domains, pillars, check IDs, or gate semantics in this RFC.

Alternatives considered

- Wait for an external contributor to file the first RFC — rejected; publisher should demonstrate the path.

- Only document the process without an index — rejected; opacity remains.

Compatibility

Additive only. Existing check IDs and profiles unchanged. Spec consumers gain an optional `rfcs` (or site index) surface; normative gate behavior unchanged.

Security considerations

None beyond clarifying that RFCs and self-assessments are not certification.

Open questions

- Should accepted RFCs auto-bump `APRF_GOVERNANCE.version` via release notes only, or require a paired implementation PR before `accepted`?

- Interim advisory board membership criteria for the next stewardship phase.

Checklist

- [x] Problem and affected parties

- [x] Proposed change stated

- [x] SemVer impact justified

- [x] Compatibility / deprecation plan

- [x] Checks remain measurable (N/A — editorial)

- [x] Crosswalk impact noted (N/A)

- [x] Security / safety considered

- [x] Open questions listed

Comment window: 14 days from `Created`. Interim contact: see `/aprf/rfc/`.