Address code review feedback - safer type checking

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/view/treeNodes/fileChangeNode.ts

@@ -163,7 +163,9 @@ export class FileChangeNode extends TreeNode implements vscode.TreeItem {
 		let current = this.parent;
 		while (current instanceof TreeNode) {
 			// CommitNode has contextValue set to 'commit'
-			if ((current as vscode.TreeItem).contextValue === 'commit') {
+			// Since TreeNode doesn't define contextValue, we check if it exists and equals 'commit'
+			const treeItem = current as { contextValue?: string };
+			if (treeItem.contextValue === 'commit') {
 				return true;
 			}
 			current = current.parent;

src/view/treeNodes/treeUtils.ts

@@ -35,6 +35,7 @@ export namespace TreeUtils {
 					continue;
 				}
 				if (!checkedNodes.includes(selected) && !uncheckedNodes.includes(selected)) {
+					// Only process files that have checkboxes (files without checkboxState, like those under commits, are skipped)
 					if (selected.checkboxState?.state === vscode.TreeItemCheckboxState.Unchecked) {
 						checkedNodes.push(selected);
 					} else if (selected.checkboxState?.state === vscode.TreeItemCheckboxState.Checked) {