style: trim comments and take the namespace builders to house signatures

The kind constants and the boundary tests said the same thing in several
places; one explanation each now. The builder methods take `Vec<String>`
like every other `namespace` builder in the crate.

nodejs/lancedb/materialized_view.ts

@@ -80,9 +80,7 @@ export function definitionFromMetadata(
   }
   // biome-ignore lint/suspicious/noExplicitAny: raw JSON
   const value: any = JSON.parse(raw);
-  // "select" is the root-namespace form; "namespaced_select" carries a
-  // source namespace, a separate kind so older readers refuse it rather
-  // than silently resolving the source at the root.
+  // "namespaced_select" keeps older readers from resolving the source at root.
   if (value.kind !== "select" && value.kind !== "namespaced_select") {
     throw new Error(
       `materialized view '${name}' is defined by '${value.kind}', which this ` +