Remove duplicate chat refs and ensure to include summary text if there is a prompt (#2316)

* Remove duplicate chat refs and ensure to include summary text if there is a prompt

* Update src/extension/agents/copilotcli/common/delegationSummaryService.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: DonJayamanne

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

@@ -73,7 +73,9 @@ export class ChatDelegationSummaryService implements IChatDelegationSummaryServi
 			return undefined;
 		}
 		const uri = URI.from({ scheme: SummaryFileScheme, path: l10n.t("summary"), query: sessionId });
-		const prompt = message.substring(0, index).trimEnd() || l10n.t('Complete the task as described in the {0}', `[summary](${uri.toString()})`);
+		const promptSuffix = l10n.t('Complete the task as described in the {0}', `[summary](${uri.toString()})`);
+		const promptPrefix = message.substring(0, index).trimEnd() || '';
+		const prompt = promptPrefix ? `${promptPrefix}\n\n${promptSuffix}` : promptSuffix;
 		const summary = message.substring(index);
 		this._summaries.set(uri, summary);
 		const reference: ChatPromptReference = {

src/extension/agents/copilotcli/node/copilotcliPromptResolver.ts

@@ -37,7 +37,7 @@ export class CopilotCLIPromptResolver {
 	 * @returns
 	 */
 	public async resolvePrompt(request: vscode.ChatRequest, prompt: string | undefined, additionalReferences: vscode.ChatPromptReference[], isIsolationEnabled: boolean, token: vscode.CancellationToken): Promise<{ prompt: string; attachments: Attachment[] }> {
-		const references = request.references.concat(additionalReferences);
+		const references = request.references.concat(additionalReferences.filter(ref => !request.references.includes(ref)));
 		prompt = prompt ?? request.prompt;
 		if (prompt.startsWith('/')) {
 			return { prompt, attachments: [] }; // likely a slash command, don't modify