feat(providers): Cursor API provider (crsr_ keys) and Cursor CLI passthrough (#10729)

Merged via merge-train (release/v3.8.50, batch1 2026-08-20) — static gates (typecheck/file-size/complexity/cognitive/changelog) green on the combined tree; test:unit reds observed in the boarded run were verified pre-existing on the pure release tip (unrelated flake), not caused by this PR. Thanks for the contribution!

src/app/api/cursor-cli/[...path]/route.ts

@@ -0,0 +1,14 @@
+import { handleCursorCliProxy } from "@omniroute/open-sse/handlers/cursorCliProxy.ts";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+type RouteContext = { params: Promise<{ path: string[] }> };
+
+async function proxy(request: Request, context: RouteContext): Promise<Response> {
+  const { path } = await context.params;
+  return handleCursorCliProxy(request, path ?? []);
+}
+
+export const GET = proxy;
+export const POST = proxy;