Batch independent DB queries in broker with asyncio.gather()

[artugro]

Problem

BrokerService.invoke_agent() makes 4-6 sequential database round trips per invocation:

1. get_effective_config() (broker config)
2. get_by_id() (conversation validation)
3. get_agent_by_agent_id() (agent lookup)
4. get_agent_credential() (credential fetch)
5. count_invocations_for_integration() (daily quota — now Redis, but DB fallback)
6. count_invocations_for_integration() (monthly quota — same)

Each DB round trip adds 1-3ms with connection pooling. These are mostly independent and can run concurrently.

Proposed Solution

Group independent queries using asyncio.gather():

• Parallel group 1: agent lookup + config lookup + conversation lookup (if provided)
• Parallel group 2: daily quota + monthly quota (if Redis fallback)

This should reduce broker overhead by 30-50% per invocation.

Files

• src/services/broker.py — main target