docs: declare where SQL and the SDKs apply

SQL is unavailable in the embedded library and varies on a deployment,
which serves it only when its Flight SQL endpoint is enabled and
reachable, and the SDK has to be told where that is. The page's opening
badge goes. The SDKs page declares both offerings.

Neither SDK aggregates or joins, so the parity tables no longer say they
do, and views can be created through the SDKs on a deployment. Pages that
said vector search has no SQL form now point to the version-dependent
SQL form, and COPY, which newer deployment versions refuse, is marked
as such in the reference.

docs/web/sql/dql/aggregation.mdx

@@ -112,7 +112,8 @@ estimate -- a 1% sample of a skewed column will miss rare categories entirely.
 
 ## What aggregation does not do {#not}
 
-Aggregates run over rows the query already produced. They cannot combine with
-[vector search](/search/vector-search) in one statement, because similarity
-search has no SQL form. Run the search in an SDK and aggregate its result, or
-materialize the search output first.
+Aggregates run over rows the query already produced. Whether a statement can
+include [vector search](/search/vector-search)
+[depends on the deployment](/basics/sql#no-vector-sql); where it cannot, run the
+search in an SDK and aggregate its result, or materialize the search output
+first.