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, 9 insertions, 0 deletions

diff --git a/packages/api/src/app.ts b/packages/api/src/app.ts
index ba5dabd..73d3de5 100644
--- a/packages/api/src/app.ts
+++ b/packages/api/src/app.ts
@@ -94,6 +94,15 @@ app.post("/chat/cancel", async (c) => {
 	return c.json({ success: cancelled });
 });
 
+app.post("/chat/stop", async (c) => {
+	const body = await c.req.json();
+	if (typeof body.tabId !== "string") {
+		return c.json({ error: "tabId is required" }, 400);
+	}
+	agentManager.stopTab(body.tabId);
+	return c.json({ success: true });
+});
+
 app.route("/skills", skillsRoutes);
 app.route("/models", modelsRoutes);
 app.route("/tabs", tabsRoutes);