fix(relay): keep local E2E tests independent of production upstream

Wrangler local mode retains deployment vars, so relay readiness probes were forwarded to an unavailable upstream instead of the local Durable Object. Clear that binding only in the E2E launcher.

packages/relay/src/e2e.test.ts

@@ -56,6 +56,9 @@ function spawnRelayDevServer(port: number): ChildProcess {
       wranglerCliPath,
       "dev",
       "--local",
+      // Local execution still inherits production vars; exercise the local Durable Object.
+      "--var",
+      "PASEO_RELAY_UPSTREAM:",
       "--ip",
       "127.0.0.1",
       "--port",