Display all model call information in message info dialog

[larryro]

Problem

Chat page only shows the routing model, but not the sub-agent models. When a user sends a message:

1. Routing model (Chat Agent) processes and routes to sub-agents
2. Sub-agents (CRM, Web, Integration, etc.) use their own models
3. Only the routing model is displayed in the message info dialog

Key Discovery

Sub-agents DO save their metadata via onAgentComplete, but to their own sub-thread, not the parent chat thread. The metadata exists but is not aggregated to the main message info dialog.

Proposed Solution

Instead of passing model info through tool responses, have sub-agents directly append their model info to the parent thread's messageMetadata record via onAgentComplete.

Acceptance Criteria

• Message info dialog shows all model calls (routing + sub-agents)
• Each sub-agent call displays: agent type, model, provider, token usage
• Works with auto-create/append for timing issues (sub-agent may complete before parent)

[larryro]

Implementation Plan

Step 1: Update OnAgentCompleteArgs Interface

File: services/platform/convex/lib/agent_completion/on_agent_complete.ts

• Add parentThreadId?: string to OnAgentCompleteArgs interface

Step 2: Create appendSubAgentUsage Mutation

File: services/platform/convex/message_metadata/mutations.ts

• Add new mutation appendSubAgentUsage that:
  • Takes parentThreadId, toolName, model, provider, usage
  • Query latest messageMetadata by parentThreadId using by_threadId index
  • If exists: append to existing subAgentUsage array
  • If not exists: create new record with only subAgentUsage (other fields will be filled by parent's onComplete later)

Step 3: Update onAgentComplete to Append to Parent

File: services/platform/convex/lib/agent_completion/on_agent_complete.ts

• If parentThreadId exists (is a sub-agent call):
  • Call appendSubAgentUsage mutation with sub-agent's model info
  • Use agentType as toolName (e.g., "document", "crm", "web")

Step 4: Pass parentThreadId to onAgentComplete

File: services/platform/convex/lib/agent_response/generate_response.ts

• Update onAgentComplete call (line 404-418) to include parentThreadId

Step 5: Update Database Schema

File: services/platform/convex/streaming/schema.ts

• Add model: v.optional(v.string()) and provider: v.optional(v.string()) to subAgentUsage

Step 6: Update saveMessageMetadata Validator

File: services/platform/convex/message_metadata/mutations.ts (lines 32-40)

• Add model and provider fields to subAgentUsage validator

Step 7: Update Client Hook

File: services/platform/app/features/chat/hooks/use-message-metadata.ts

• Add subAgentUsage to returned metadata interface

Step 8: Update Message Info Dialog UI

File: services/platform/app/features/chat/components/message-info-dialog.tsx

• Add interface for SubAgentUsage
• Render sub-agent calls section showing: agent type, model, provider, tokens

Step 9: Add Translations

File: services/platform/messages/en.json

• Add: "messageInfo.subAgentCalls": "Sub-agent calls"

Verification

1. Send a chat message that triggers sub-agents (e.g., CRM query, web search)
2. Click info button (ℹ️) on assistant message
3. Verify:
   • Main model info is displayed
   • Sub-agent calls section shows each sub-agent with its model
   • Token usage shown per sub-agent