[jipeng6036-del]

Full-rewrite responses with a space or tab after the opening fence language fall through to the generic fence parser. That leaves python in the extracted program and causes evaluation to fail with NameError.

I allow trailing horizontal whitespace in the language-specific parser and added a regression that executes the extracted function across spaces/tabs and LF/CRLF endings.

Validation:

• Full unit suite on Linux/Python 3.10: 701 tests, 2 skipped; the unchanged baseline also passes.
• Full integration suite against the real local codelion/dhara-250m model: 41 passed. The unmodified repository CI passes both jobs at this exact commit.
• Repository isort/Black hooks pass.
• Ran the actual CLI, process worker, evaluator and checkpoint path against a loopback response fixture: ordinary fences work before and after; whitespace variants fail before and return the expected result after.

[CLAassistant]

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