fix: use getTitle() to find nodes by display name in getNodeRefsByTitle

The getNodeRefsByTitle function was using n.title === title, which only
works for nodes with an explicitly set title property. Nodes without a
custom title (most nodes) fall back to constructor.title, which is set
from the node's display_name during registration.

Using getTitle() instead properly returns this.title || this.constructor.title,
allowing selectNodes to work with display names like 'VAE Decode' and
'Load Checkpoint'.

Amp-Thread-ID: https://ampcode.com/threads/T-019c17d8-6930-748a-bd55-2370f17af8ea

browser_tests/fixtures/ComfyPage.ts

@@ -1605,7 +1605,7 @@ export class ComfyPage {
       (
         await this.page.evaluate((title) => {
           return window['app'].graph.nodes
-            .filter((n: LGraphNode) => n.title === title)
+            .filter((n: LGraphNode) => n.getTitle() === title)
             .map((n: LGraphNode) => n.id)
         }, title)
       ).map((id: NodeId) => this.getNodeRefById(id))