feat: support channel routing to dispatch messages to different agents

[ixiadao]

Summary

Add channel routing support to dispatch channel messages to different agents based on configurable rules. This enables a single channel (e.g. one Feishu bot) to serve multiple agents by routing messages based on meta fields like feishu_chat_id.

Changes

config/config.py

• Add ChannelRoutingRule model with fields: channel, match_field, match_value, target_agent_id
• Add channel_routing field to AgentsConfig

app/channels/base.py

• Add _channel_routing_rules and _multi_agent_manager to BaseChannel.__init__
• Add _resolve_channel_routing() to match meta fields against routing rules
• Add _get_routed_process() to get the target agent's stream_query handler
• Modify _run_process_loop() to use routed process when a rule matches

app/channels/feishu/channel.py

• Override _run_process_loop() to support channel routing (Feishu overrides the base method, so routing must be added here too)

app/_app.py

• Inject routing rules and multi_agent_manager into default agent's channels during startup

Configuration Example

{
  "agents": {
    "channel_routing": [
      {
        "channel": "feishu",
        "match_field": "feishu_chat_id",
        "match_value": "oc_xxxx",
        "target_agent_id": "agent_1"
      }
    ]
  }
}

Use Case

When running multiple agents, users often want a single Feishu bot (one App) to serve different agents in different group chats. This PR enables that by routing messages based on the group chat ID to the appropriate agent.

Testing

• Tested with 3 routing rules (3 Feishu group chats → 3 different agents)
• Messages in each group are correctly routed to the target agent
• Messages in unmatched chats (e.g. DM) fall through to the default agent
• No impact on channels without routing rules configured