Complete backend infrastructure and authentication system

Co-authored-by: mblanke <9078342+mblanke@users.noreply.github.com>

backend/app/schemas/auth.py

@@ -0,0 +1,29 @@
+from pydantic import BaseModel
+from typing import Optional
+
+
+class Token(BaseModel):
+    """Token response schema"""
+    access_token: str
+    token_type: str = "bearer"
+
+
+class TokenData(BaseModel):
+    """Token payload data"""
+    user_id: Optional[int] = None
+    tenant_id: Optional[int] = None
+    role: Optional[str] = None
+
+
+class UserLogin(BaseModel):
+    """User login request schema"""
+    username: str
+    password: str
+
+
+class UserRegister(BaseModel):
+    """User registration request schema"""
+    username: str
+    password: str
+    tenant_id: Optional[int] = None
+    role: str = "user"