feat: wire multi-agent config and routing

Co-authored-by: Mark Pors <1078320+pors@users.noreply.github.com>

src/agents/clawdbot-gateway-tool.test.ts

@@ -46,7 +46,7 @@ describe("gateway tool", () => {
     expect(tool).toBeDefined();
     if (!tool) throw new Error("missing gateway tool");
 
-    const raw = '{\n  agent: { workspace: "~/clawd" }\n}\n';
+    const raw = '{\n  agents: { defaults: { workspace: "~/clawd" } }\n}\n';
     await tool.execute("call2", {
       action: "config.apply",
       raw,