feat: add openclaw_gateway adapter

New adapter type for invoking OpenClaw agents via the gateway protocol.
Registers in server, CLI, and UI adapter registries. Adds onboarding
wizard support with gateway URL field and e2e smoke test script.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/adapters/openclaw-gateway/src/shared/stream.ts

@@ -0,0 +1,16 @@
+export function normalizeOpenClawGatewayStreamLine(rawLine: string): {
+  stream: "stdout" | "stderr" | null;
+  line: string;
+} {
+  const trimmed = rawLine.trim();
+  if (!trimmed) return { stream: null, line: "" };
+
+  const prefixed = trimmed.match(/^(stdout|stderr)\s*[:=]?\s*(.*)$/i);
+  if (!prefixed) {
+    return { stream: null, line: trimmed };
+  }
+
+  const stream = prefixed[1]?.toLowerCase() === "stderr" ? "stderr" : "stdout";
+  const line = (prefixed[2] ?? "").trim();
+  return { stream, line };
+}