docs: audit pass — drop pre-0.7.0 release notes; scrub RFC refs from user docs (#272)

* docs: audit pass — drop pre-0.7.0 release notes; scrub RFC refs from user docs

- Delete the pre-0.7.0 release-notes archive (v0.2.0 … v0.6.2); keep v0.7.0.
- Rewrite every inline "RFC-0NN" citation in docs/user/** into durable
  plain language (the behavior is the contract, not the planning doc):
  cli/index.md, cli/reference.md, clusters/index.md, operations/{maintenance,
  policy,server}.md. Updated the in-page "Scopes & profiles" anchor to match
  the de-RFC'd heading.

No sub-0.7.0 version caveats or stale Lance-version refs were present in
docs/user/**. Dev docs, AGENTS.md, and instruction files are out of scope for
this pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: second alignment pass — drop residual pre-cluster-only framing

- cli/reference.md: rewrite the server-scope graph-resolution rule — an
  omnigraph-server is always cluster-backed, so GET /graphs always answers and
  --graph is required; the bare-URL path is only the fallback for an
  unavailable/non-omnigraph endpoint (was "a single-graph / flat server …
  uses its bare URL as before").
- embeddings.md: "Direct single-graph serving" → "Direct (--store) access"
  (there is no single-graph serving mode under cluster-only).
- clusters/{config,index}.md: drop the removed --target flag from the
  "--cluster cannot combine with …" clauses.

Verified: no Linear tickets, no RFC refs, no single-graph-as-current, no
--target-as-combinable in docs/user/**.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

docs/user/cli/index.md

@@ -14,7 +14,7 @@ omnigraph mutate insert_person --params '{"name":"Mina","age":28}'
 `omnigraph query` is the canonical read command (pairs with `POST /query`);
 `omnigraph mutate` is the canonical write command (pairs with `POST /mutate`).
 The positional argument is the **stored-query name**, invoked from the served
-catalog (RFC-011 D3) — the graph is addressed by scope (`--server` / `--profile`
+catalog — the graph is addressed by scope (`--server` / `--profile`
 / defaults), and the verb asserts the query's kind (`query` rejects a stored
 mutation, and vice-versa). The previous names `omnigraph read` and
 `omnigraph change` keep working as visible aliases — invocations emit a one-line