feat: HVAC ductwork + DWV plumbing systems (#402)

Adds two new MEP node families (HVAC ductwork, DWV plumbing) built on a shared port-connectivity model. Co-authored by @sudhir9297.

packages/nodes/src/cupola/preview.tsx

@@ -13,6 +13,7 @@ import type { CupolaNode } from './schema'
  * so the preview doesn't intercept the cursor ray feeding the tool.
  */
 const CupolaPreview = ({ node, invalid }: { node: CupolaNode; invalid?: boolean }) => {
+  // biome-ignore lint/correctness/useExhaustiveDependencies: deps deliberately list the build inputs; depending on the whole object would rebuild on unrelated field changes.
   const geometry = useMemo(
     () => buildCupolaGeometry(node),
     [node.width, node.depth, node.height, node.roofStyle, node.finial],

packages/nodes/src/cupola/renderer.tsx

@@ -53,6 +53,7 @@ const CupolaRenderer = ({ node: storeNode }: { node: CupolaNode }) => {
       : undefined,
   )
 
+  // biome-ignore lint/correctness/useExhaustiveDependencies: deps deliberately list the build inputs; depending on the whole object would rebuild on unrelated field changes.
   const geometry = useMemo(
     () => buildCupolaGeometry(node),
     [node.width, node.depth, node.height, node.roofStyle, node.finial],