fix(tts): gated playback clearing to user messages

Moved vocalizer interruption from agent_start to user message_start so agentLoopContinue preserves queued speech.

Expanded regression coverage for continuation starts and user prompt boundaries.

Fixes #6375

packages/coding-agent/CHANGELOG.md

@@ -4,7 +4,7 @@
 
 ### Fixed
 
-- Fixed Assistant-mode TTS playback aborting when an agent continued after a tool call in the same run; internal turn boundaries now preserve queued speech, while a new agent run still interrupts prior playback. ([#6375](https://github.com/can1357/oh-my-pi/issues/6375))
+- Fixed Assistant-mode TTS playback aborting when an agent continued after a tool call or automatic follow-up in the same run; internal continuation boundaries now preserve queued speech, while a new user message still interrupts prior playback. ([#6375](https://github.com/can1357/oh-my-pi/issues/6375))
 - Fixed credential-shaped tokens (GitHub/GitLab/OpenAI/Anthropic key patterns) being redacted from outbound provider requests even with `secrets.enabled` off; the pattern redaction now follows the `secrets.enabled` ("Hide Secrets") setting like the secret obfuscator.
 - Fixed Ctrl-clicking a wrapped OAuth authorization URL opening only the clicked row's truncated fragment by preserving the complete hyperlink target on every rendered row.
 - Fixed used-only absolute usage amounts across output surfaces: CLI now renders `$123.45 used`; the TUI shows a neutral, width-bounded amount instead of a pending/dotted/account-count placeholder; and ACP preserves `123.45 usd used` while suppressing duplicate window suffixes such as `— extra`. ([#5575](https://github.com/can1357/oh-my-pi/issues/5575))

packages/coding-agent/src/modes/controllers/event-controller.ts

@@ -405,7 +405,6 @@ export class EventController {
 	}
 
 	async #handleAgentStart(_event: Extract<AgentSessionEvent, { type: "agent_start" }>): Promise<void> {
-		vocalizer.clear();
 		this.#toolTimelineComponents.clear();
 		this.#postToolAssistantComponents.clear();
 		this.#lastIntent = undefined;
@@ -450,6 +449,7 @@ export class EventController {
 			}
 			this.ctx.ui.requestRender();
 		} else if (event.message.role === "user") {
+			vocalizer.clear();
 			const textContent = this.ctx.getUserMessageText(event.message);
 			const imageBlocks =
 				typeof event.message.content === "string"

packages/coding-agent/test/modes/controllers/event-controller-interrupt.test.ts

@@ -22,6 +22,11 @@ function createContext() {
 		transcriptMessageComponents: new WeakMap(),
 		pendingTools,
 		hideThinkingBlock: false,
+		getUserMessageText: () => "new prompt",
+		locallySubmittedUserSignatures: new Set<string>(),
+		addMessageToChat: vi.fn(),
+		editor: { setText: vi.fn() },
+		updatePendingMessagesDisplay: vi.fn(),
 		setWorkingMessage,
 		clearPinnedError: vi.fn(),
 		ensureLoadingAnimation,
@@ -62,15 +67,24 @@ describe("EventController aborted-turn working messages", () => {
 		resetSettingsForTest();
 	});
 
-	it("preserves playback across internal turns and clears it for a new agent run", async () => {
+	it("preserves playback across internal continuations and clears it for a user message", async () => {
 		const clear = vi.spyOn(vocalizer, "clear").mockImplementation(() => {});
 		const { ctx } = createContext();
 		const controller = new EventController(ctx);
 
+		await controller.handleEvent(AGENT_START);
 		await controller.handleEvent({ type: "turn_start" });
 		expect(clear).not.toHaveBeenCalled();
 
-		await controller.handleEvent(AGENT_START);
+		await controller.handleEvent({
+			type: "message_start",
+			message: {
+				role: "user",
+				content: [{ type: "text", text: "new prompt" }],
+				attribution: "user",
+				timestamp: Date.now(),
+			},
+		});
 		expect(clear).toHaveBeenCalledTimes(1);
 	});