docs(rfc): RFC-009 — unify CLI access paths; align the RFC corpus

Adopts the unify-embedded/remote draft as RFC-009 with three alignment
amendments: (1) the promised 'companion config-authority RFC' is RFC-008,
already landed through stage 4 — referenced, not re-proposed; (2) open
question 3 is answered by the two-surface architecture (embedded graphs
list enumerates the cluster catalog via read_serving_snapshot, never
omnigraph.yaml); (3) Phase 2 salvages PR #139's reviewed-clean
omnigraph-api-types extraction instead of rebuilding. Adds the
cycle's two no-referee bugs (alias positional, write-if-absent flush) as
concrete parity-matrix motivation, and RFC-007's addressing/credential
chains as RemoteClient constructor inputs.

Corpus alignment: RFC-002's header now maps each of its pieces to the
successor that landed or superseded it (007/008/009) with a do-not-
implement-from-here-unchecked warning; RFC-007 gains the RFC-009
relationship; RFC-008 stage 5 notes the Phases-4/5 easing; dev index row.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/dev/rfc-007-operator-config.md

@@ -319,6 +319,12 @@ Every mention of `omnigraph.yaml` in this RFC describes the deprecation
 window only. Sequencing couples them: RFC-007 PRs 1–2 land first, then
 RFC-008's migration stages run against them.
 
+[rfc-009-unify-access-paths.md](rfc-009-unify-access-paths.md) consumes
+this RFC's surfaces: the actor chain and keyed-credential chain become
+constructor-time inputs of its `RemoteClient`/`EmbeddedClient`, and
+`--server`/operator aliases resolve to the same (base URL, credential)
+pair before its `GraphClient` trait is touched.
+
 RFC-002 remains the umbrella architecture. This RFC implements its §2
 (layered config, global-first), §4 (file naming / one dir), and §5
 (credentials) in their minimal load-bearing form, and explicitly defers §1