Fix 'Hide Ghost Requests' not filtering ghost prompt groups

The ghost request filter in the Chat Debug Log only checked ChatRequestItem
instances but not ChatPromptItem (parent grouping nodes). This meant ghost
prompt groups labeled 'Ghost' or 'Ghost | ...' remained visible even with
the filter active.

Extend isGhostRequest to also handle ChatPromptItem, matching the pattern
already used for NES request filtering.

Fixes microsoft/vscode#297566

Author: ulugbekna

src/extension/log/vscode-node/requestLogTree.ts

@@ -862,6 +862,9 @@ class LogTreeFilters extends Disposable {
 			if (this.isNesRequest(item)) {
 				return this._nesRequestsShown;
 			}
+			if (this.isGhostRequest(item)) {
+				return this._ghostRequestsShown;
+			}
 			return true; // Always show chat prompt items
 		} else if (item instanceof ChatElementItem) {
 			return this._elementsShown;
@@ -881,8 +884,14 @@ class LogTreeFilters extends Disposable {
 		return true;
 	}
 
-	private isGhostRequest(item: ChatRequestItem): boolean {
-		const debugName = item.info.entry.debugName.toLowerCase();
+	private isGhostRequest(item: ChatPromptItem | ChatRequestItem): boolean {
+		let debugName: string;
+		if (item instanceof ChatPromptItem) {
+			assert(typeof item.label === 'string', 'ChatPromptItem label must be a string');
+			debugName = item.label.toLowerCase();
+		} else {
+			debugName = item.info.entry.debugName.toLowerCase();
+		}
 		return debugName === 'ghost' || debugName.startsWith('ghost |');
 	}