Moved endpoints to routers

app/routers/auth.py

@@ -0,0 +1,22 @@
+from fastapi import APIRouter
+from app.auth.cognito import initiate_auth
+from app.models.auth import SigninRequest, TokenResponse
+
+router = APIRouter(
+    prefix="/auth",
+    tags=["authentication"]
+)
+
+@router.post("/signin", response_model=TokenResponse, summary="Signin Endpoint")
+def signin(credentials: SigninRequest):
+    """
+    Sign-in endpoint to authenticate the user with AWS Cognito using username and password.
+    On success, returns JWT tokens (access_token, id_token, refresh_token).
+    """
+    auth_result = initiate_auth(credentials.username, credentials.password)
+    return TokenResponse(
+        access_token=auth_result["AccessToken"],
+        id_token=auth_result["IdToken"],
+        refresh_token=auth_result.get("RefreshToken"),
+        token_type="Bearer",
+    )