network() stream doesn't forward reasoning events from sub-agents

@mastra/core: beta
@mastra/ai-sdk: beta
Model: anthropic/claude-haiku-4-5

// chat-agent.ts - Parent agent with sub-agent
export const chatAgent = new Agent({
  id: 'chat-agent',
  instructions: {
    role: 'system',
    content: 'You are a router...',
    providerOptions: {
      anthropic: {
        thinking: { type: 'enabled', budgetTokens: 4000 }
      }
    }
  },
  model: 'anthropic/claude-haiku-4-5',
  agents: { strategist: strategistAgent }
});
// Test script
const stream = await chatAgent.network('Hello', { memory: { thread: 'test' } });
for await (const chunk of stream) {
  console.log(chunk.type);
  // Never see: agent-execution-event-reasoning-delta
  // Do see: agent-execution-event-text-delta
}