test(coding-agent): stub setTextOutputCommitted in print mocks

Added the no-op setter to lightweight print-mode session mocks so text-mode runs without a submitted prompt no longer throw at the final commit call.

Fixes #7625

packages/coding-agent/test/modes/noninteractive-dispose.test.ts

@@ -40,6 +40,7 @@ describe("print-mode error exit disposes the session before exit", () => {
 			state: { messages: [errorMsg] },
 			getLastAssistantMessage: () => errorMsg,
 			prepareForHeadlessAdvisorDrain: () => {},
+			setTextOutputCommitted: () => {},
 			waitForAdvisorCatchup: async () => {
 				order.push("catchup");
 				return true;

packages/coding-agent/test/silent-abort-print-mode.test.ts

@@ -55,6 +55,7 @@ function createMockSession(
 		subscribe: () => () => {},
 		prompt: async () => {},
 		prepareForHeadlessAdvisorDrain: () => {},
+		setTextOutputCommitted: () => {},
 		waitForAdvisorCatchup: async () => true,
 		dispose,
 	} as unknown as AgentSession;