CreateAgent does not register identity — breaks agent SendMessage

[rowan-stein]

User Request

Chat-app e2e test chat-agent-response.spec.ts fails: agent daemon exits with sender_id: identity not found when sending messages. Agent identities are never registered in the identity service.

Specification

Problem

agents.CreateAgent stores the agent in the DB and writes authorization membership, but never calls identity.RegisterIdentity. When the agent daemon later sends messages via threads.SendMessage(senderID=agentID), threads validates identity.GetIdentityType(agentID) → NotFound → "sender_id: identity not found".

Three other services already register identities: users (USER), apps (APP), runners (RUNNER). Agents is the missing one.

Fix

1. Add identityClient identityv1.IdentityServiceClient to the Server struct in agents/internal/server/server.go
2. In CreateAgent, after successful store.CreateAgent and addAgentMembership, call:

_, err = s.identityClient.RegisterIdentity(ctx, &identityv1.RegisterIdentityRequest{
    IdentityId:   agent.Meta.ID.String(),
    IdentityType: identityv1.IdentityType_IDENTITY_TYPE_AGENT,
})
if err != nil {
    // Rollback: remove membership and agent
    _ = s.store.DeleteAgent(ctx, agent.Meta.ID)
    return nil, status.Errorf(codes.Internal, "register identity: %v", err)
}

3. Update agents/cmd/ entrypoint to create the gRPC client for identity:50051 and pass it to server.New()
4. Follow the same pattern as users.CreateUser, apps.RegisterApp, and runners.RegisterRunner