add orchestrator / tatlock distinction to docs

AGENTS.md

@@ -13,7 +13,7 @@ This project implements an OpenAI-compatible API endpoint using FastAPI, with st
 
 ### Current Architecture (As of 2025-12-06)
 
-This project implements a **hybrid architecture** with the Responses API as the primary endpoint and Chat Completions as a compatibility wrapper:
+This project implements the **Orchestrator** infrastructure layer with a hybrid API architecture:
 
 ```
 Client (Open WebUI)
@@ -22,9 +22,24 @@ Chat Completions (/v1/chat/completions) → Wrapper
       ↓
 Responses API (/v1/responses) → Primary
       ↓
-Agent Interface (lorem-tester, tatlock)
+Agent Interface (lorem-tester, Tatlock)
+      ↓
+Mock Agents (lorem-tester) / Future: PydanticAI Agents (Tatlock, Steward, etc.)
 ```
 
+**Architectural Layers:**
+
+1. **The Orchestrator** (Current Implementation)
+   - FastAPI application providing the infrastructure
+   - HTTP/SSE endpoints, streaming coordination
+   - Conversation history and context management
+   - OpenAI-compatible API surface
+
+2. **Future: The Household** (Phases 1-4)
+   - **Steward**: First-tier LLM for request analysis (PydanticAI agent)
+   - **Tatlock**: Second-tier LLM with butler personality (PydanticAI agent)
+   - **Expert Agents**: Domain specialists (Librarian, Developer, Handyman, etc.)
+
 **Key Architectural Decisions:**
 
 1. **Single Source of Truth**: All response generation happens in the Responses API
@@ -45,7 +60,7 @@ Agent Interface (lorem-tester, tatlock)
      - Random tool/function calls
      - Error triggers for testing
      - Temperature variation
-   - **tatlock**: Placeholder for future PydanticAI agent
+   - **Tatlock**: Advertised model name (currently mock, future: PydanticAI Butler agent)
 
 4. **Hybrid Conversation History**:
    - Client MUST send full context in `input` array (OpenAI compatible)