Phase 3 Mission:
Generate detailed API reference documentation for chat, channels, memories, and notes endpoints.

Prerequisites:
- api_docs/00_route_index.md must already exist (from Phase 1).

Source files to read (fully):
- backend/open_webui/routers/chats.py
- backend/open_webui/routers/channels.py
- backend/open_webui/routers/memories.py
- backend/open_webui/routers/notes.py
- backend/open_webui/models/chats.py        (Pydantic models)
- backend/open_webui/models/channels.py
- backend/open_webui/models/memories.py
- backend/open_webui/models/notes.py (if exists)
- backend/open_webui/models/messages.py (shared message models)

Output files to create under api_docs/:
- 03_chats.md
- 03_channels.md
- 03_memories.md
- 03_notes.md

Per-endpoint format:

---

### {HTTP_METHOD} {full_path}

**Summary:** One sentence description.

**Auth:** Admin only | Verified user | Public

**Request**

| Location | Field | Type | Required | Description |
|----------|-------|------|----------|-------------|
| Body | field_name | type | Yes/No | description |

*If no parameters, write: "No additional parameters."*

**Response `200`**

```json
{
  "example_field": "example_value"
}
```

| Field | Type | Description |
|-------|------|-------------|
| field_name | type | description |

**Error Responses**

| Status | Meaning |
|--------|---------|
| 401 | Not authenticated |
| 403 | Insufficient permissions |
| 404 | Resource not found |

---

Special notes for this phase:
- chats.py is 1527 lines with ~40 routes — document ALL of them.
- channels.py is 2133 lines — document ALL routes; note WebSocket upgrade endpoints separately.
- For WebSocket endpoints: note the protocol (ws://) and describe events/message payload format.
- Pay special attention to chat history structure: messages array, history.messages dict.
- Note pagination parameters (skip, limit, page) where applicable.

Instructions:
1. Read each router file fully.
2. Trace Pydantic model definitions from the corresponding models/ file.
3. For complex response types (list of chats, paginated results), show the wrapper structure.
4. If a route modifies chat history, document the exact history object shape.
5. List ALL endpoints — do not skip paginated variants.

Exit Criteria:
- 4 output files created.
- Every route from 00_route_index.md for these modules is covered.
- WebSocket endpoints documented with payload shape.
- No placeholder or TBD.

Final output format:
- List of files created.
- Count of endpoints documented per file.
- Note any complex schemas that required deep tracing.
