feat(01-02): extract agent config and sandbox setup into src/daemon/agents.ts

- Create initAgents() function encapsulating AgentConfigRegistry, AgentRouter, SandboxManager init
- Replace ~26 lines in startDaemon() with single initAgents() call
- Lifecycle shutdown handler for sandbox cleanup included in agents.ts
- Zero type errors, routing tests pass

src/daemon/agents.ts

@@ -0,0 +1,48 @@
+import type { Config } from '../config/index.js';
+import { AgentConfigRegistry, AgentRouter } from '../agents/index.js';
+import { DockerSandbox, SandboxManager } from '../sandbox/index.js';
+import type { Lifecycle } from './lifecycle.js';
+
+export interface AgentsDeps {
+  config: Config;
+  lifecycle: Lifecycle;
+}
+
+export interface AgentsResult {
+  agentConfigRegistry: AgentConfigRegistry;
+  agentRouter: AgentRouter;
+  sandboxManager?: SandboxManager;
+}
+
+export async function initAgents(deps: AgentsDeps): Promise<AgentsResult> {
+  const { config, lifecycle } = deps;
+
+  // Initialize agent config registry and router
+  const agentConfigRegistry = new AgentConfigRegistry();
+  if (config.agent_configs && Object.keys(config.agent_configs).length > 0) {
+    agentConfigRegistry.loadFromConfig(config.agent_configs);
+    console.log(`Loaded ${Object.keys(config.agent_configs).length} agent config(s)`);
+  }
+  const agentRouter = new AgentRouter(config.routing);
+
+  // Initialize sandbox manager if Docker is available
+  let sandboxManager: SandboxManager | undefined;
+  if (config.sandbox.enabled) {
+    const dockerAvailable = await DockerSandbox.isAvailable();
+    if (dockerAvailable) {
+      sandboxManager = new SandboxManager(config.sandbox);
+      console.log(`Docker sandbox enabled (image=${config.sandbox.image}, network=${config.sandbox.network})`);
+    } else {
+      console.warn('Docker sandbox enabled but Docker not available — falling back to host execution');
+    }
+  }
+
+  if (sandboxManager) {
+    lifecycle.onShutdown(async () => {
+      await sandboxManager!.destroyAll();
+      console.log('Docker sandboxes destroyed');
+    });
+  }
+
+  return { agentConfigRegistry, agentRouter, sandboxManager };
+}