fix: extract attributes for heuristically-detected interactive elements

Elements detected as interactive via heuristic methods (cursor:pointer
style, interactive class names, event listeners) had empty attributes
because `isInteractiveCandidate()` was used as the gate for attribute
extraction. This function only recognizes standard HTML tags and ARIA
attributes, missing heuristic detections.

After interactivity is confirmed by `isInteractiveElement()`, backfill
attributes for elements that were missed. This ensures
`includeAttributes` (e.g. `['class']`) works correctly for all
interactive elements, not just semantically standard ones.

Closes #124

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/page-controller/src/dom/dom_tree/index.js

@@ -1608,6 +1608,18 @@ export default (
 					 * @edit direct dom ref
 					 */
 					nodeData.ref = node
+
+					// Extract attributes for heuristically-detected interactive elements
+					// isInteractiveCandidate() only covers standard tags and ARIA attributes,
+					// so elements detected via cursor:pointer, class names, or event listeners
+					// may have empty attributes. Fill them in so include_attributes works.
+					if (nodeData.isInteractive && Object.keys(nodeData.attributes).length === 0) {
+						const attributeNames = node.getAttributeNames?.() || []
+						for (const name of attributeNames) {
+							const value = node.getAttribute(name)
+							nodeData.attributes[name] = value
+						}
+					}
 				}
 			}
 		}