fix(schema): validate input_node_uuid as UUID in CreateOperationNodePayload

[sentry]

The CreateOperationNodePayload schema for /api/transform/v2/dbt_project/operations/nodes/ previously defined input_node_uuid as a generic str. This allowed non-UUID strings, such as frontend-generated temporary IDs like dummy-<uuid>, to be passed to the backend.

This change updates the input_node_uuid field in CreateOperationNodePayload from str to UUID. This ensures that the API payload is validated at the schema level, rejecting any non-UUID values early with a 422 Unprocessable Entity error, thus preventing the ValidationError from reaching the ORM layer. This provides a clearer error message and enforces data integrity.

Fixes DALGO-BACKEND-2HV

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.26%. Comparing base (11a5843) to head (20cbf64).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1415   +/-   ##
=======================================
  Coverage   60.26%   60.26%           
=======================================
  Files         146      146           
  Lines       17222    17222           
=======================================
  Hits        10378    10378           
  Misses       6844     6844           

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