edits: fix hydrated edits from background sessions missing stops

Core merges seqential markdown blocks together. In normal edits they're broken up by (hidden) tool call parts for edits, but this was not the case for background agents. Simplest change is just making background agent edits work the same way as normal edits by emitting the tool call part.

Closes microsoft/vscode#281633

Author: connor4312

src/extension/agents/copilotcli/common/copilotCLITools.ts

@@ -384,12 +384,14 @@ export function buildChatHistoryFromEvents(sessionId: string, events: readonly S
 					const editId = details?.toolIdEditMap ? details.toolIdEditMap[toolCall.toolCallId] : undefined;
 					const editedUris = getAffectedUrisForEditTool(toolCall);
 					if (isCopilotCliEditToolCall(toolCall) && editId && editedUris.length > 0) {
+						responsePart.presentation = 'hidden';
+						currentResponseParts.push(responsePart);
 						for (const uri of editedUris) {
 							currentResponseParts.push(new ChatResponseMarkdownPart('\n````\n'));
 							currentResponseParts.push(new ChatResponseCodeblockUriPart(uri, true, editId));
-							currentResponseParts.push(new ChatResponseMarkdownPart('\n````\n'));
 							currentResponseParts.push(new ChatResponseTextEditPart(uri, []));
 							currentResponseParts.push(new ChatResponseTextEditPart(uri, true));
+							currentResponseParts.push(new ChatResponseMarkdownPart('\n````\n'));
 						}
 					} else {
 						currentResponseParts.push(responsePart);

src/extension/vscode.proposed.chatParticipantAdditions.d.ts

@@ -105,6 +105,7 @@ declare module 'vscode' {
 		isComplete?: boolean;
 		toolSpecificData?: ChatTerminalToolInvocationData;
 		fromSubAgent?: boolean;
+		presentation?: 'hidden' | 'hiddenAfterComplete' | undefined;
 
 		constructor(toolName: string, toolCallId: string, isError?: boolean);
 	}