feat: implement initial structure for activities, analytics, auth, contacts, deals, organizations, tasks, and users APIs with placeholder endpoints

app/api/v1/activities/models.py

@@ -0,0 +1,11 @@
+"""Pydantic schemas for activity endpoints."""
+from __future__ import annotations
+
+from typing import Any, Literal
+
+from pydantic import BaseModel
+
+
+class ActivityCommentPayload(BaseModel):
+    type: Literal["comment"]
+    payload: dict[str, Any]