docs: step-3 rewrites — OQ-39/40 resolved, C-08 closed, channel-operations.md put/control/resources contracts, review 010/011 closed with the S-01 sketch corrected

- open-questions.md: OQ-39 → ADR-052, OQ-40 → ADR-053 (resolutions replace
  the deferred-until-needed posture)
- channel-operations.md: the put contract (initiator allocates + streams,
  reserved input key, one response, acks-in-result sentence), the control
  routing (ADR-052), the enumerator aggregation (ADR-053), the
  connection-owner paragraph's pub-era correction, the ADR table rows
- ADR-051 §6: PubTypedOpen → the put translation; ADR-047's 2026-09-06
  amendment records its era honestly (the dynamic half is now ADR-053)
- review 010: all four findings resolved (with the S-01 sketch correction
  so the published record stops carrying the wrong-graph reading)
- review 011: closed (all seven pins implemented + gates landed)
- review 001 C-08: resolved note (odd/even + adopt, implemented)
- AGENTS.md: the 'Stub Guard' section — the not_implemented grep is part
  of cargo test; the registration invariants and the implement-or-stop
  ruling are release-blocking

Verified: cargo test (696+guard), clippy -D warnings, fmt, doc clean.

src/channels/relay.rs

@@ -132,7 +132,8 @@ impl ChannelRelay {
     /// - `spec` must carry the `channel_open` marker (reconstructed
     ///   WITH the marker by discovery, ADR-047 amendment 3). A
     ///   `Pub`-typed marked spec composes through the put-forwarding
-    ///   translation (see [`Self::register_relay_pub_openable`]); an
+    ///   translation (`register_relay_pub_openable`; ADR-047 amendment 4
+    ///   §4.7); an
     ///   unmarked spec is a
     ///   [`RelayError::UnmarkedSpec`] error — branch on the
     ///   marker before calling.