Early completion when polling Text-to-CAD

[davreev]

Related to support issue where user is getting empty output after polling a TextToCad response. See details in discussion (key finding here).

Minimal Python repro below. The first attempt with a new prompt (cache miss) produces a valid KCL with no output files. A second attempt with the same prompt (cache hit) produces valid KCL along with the expected output files.

text_to_cad_test.py

[davreev]

Update: user is reporting a similar issue when polling create_text_to_cad_iteration (link)