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/operators.mdx

@@ -44,8 +44,8 @@ IN`, which is the usual place this bites. See
 <Warning>
 Arithmetic over a vector column is **list** arithmetic, not scalar arithmetic —
 a vector is a `FixedSizeList<Float32>`. When the operation you want is a
-similarity comparison, use [vector search](/search/vector-search); there is no
-SQL form for it.
+similarity comparison, use [vector search](/search/vector-search); whether SQL
+can express it [depends on the deployment](/basics/sql#no-vector-sql).
 </Warning>
 
 ## Literals {#literals}