fix(rsg): repair the release build broken by the findNode global check (#1099)

`sgRoot.mGlobal !== this` fails to compile: mGlobal is a `Global`, which
TypeScript sees as having no overlap with the polymorphic `this`, so
`tsc`/ts-loader raise TS2367 and the brs-scenegraph build fails.

Widen to RoSGNode before comparing, the same way the earlier global-node
check did.

Only a clean build surfaces it — an incremental rebuild reuses the cached
module and reports success, which is how it reached master.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: lvcabral

src/extensions/scenegraph/components/RoSGNode.ts

@@ -1805,7 +1805,10 @@ export abstract class RoSGNode extends BrsComponent implements BrsValue, ISGNode
                 // node appended to m.global via m.global.findNode(). Skipping the self-search keeps
                 // that boundary — every other node's subtree is part of its ancestor's anyway, so
                 // searching it first is only a shortcut.
-                const searchSelf: boolean = sgRoot.mGlobal !== this;
+                // Widened to RoSGNode so the comparison type-checks: `sgRoot.mGlobal` is a `Global`,
+                // which TypeScript sees as having no overlap with the polymorphic `this`.
+                const globalNode: RoSGNode = sgRoot.mGlobal;
+                const searchSelf: boolean = globalNode !== this;
                 let node: RoSGNode | BrsInvalid = searchSelf ? this.findNodeById(this, id) : BrsInvalid.Instance;
                 if (node instanceof BrsInvalid) {
                     // if not found, search from root