feat: stop generation button with abort signal plumbing

- Add POST /chat/stop endpoint on API
- Thread abortSignal from agent-manager through Agent.run() to streamText
- Thread abortSignal option through the Agent.run() signature
- Emit status:idle on stopTab() so frontend WS gets the update
- Add stopGeneration() store method on frontend tabStore
- Add stop button in ChatInput (btn-sm lg:btn-xs for mobile tap target)
- Add tests for /chat/stop endpoint
- Refactor processMessage to pass abortSignal to agent.run

1 files changed, 22 insertions, 0 deletions

diff --git a/packages/api/tests/routes.test.ts b/packages/api/tests/routes.test.ts
index 49bae49..eba2226 100644
--- a/packages/api/tests/routes.test.ts
+++ b/packages/api/tests/routes.test.ts
@@ -318,3 +318,25 @@ describe("POST /chat", () => {
 		expect(typeof body.messageId).toBe("string");
 	});
 });
+
+describe("POST /chat/stop", () => {
+	it("returns 200 with success: true for valid tabId", async () => {
+		const res = await app.request("/chat/stop", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({ tabId: "tab-stop-1" }),
+		});
+		expect(res.status).toBe(200);
+		const body = await res.json();
+		expect(body).toEqual({ success: true });
+	});
+
+	it("returns 400 when tabId is missing", async () => {
+		const res = await app.request("/chat/stop", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({}),
+		});
+		expect(res.status).toBe(400);
+	});
+});