Fix banana pudding recipe model

[CleanDev-Fix]

Summary

• Implements the missing Python banana pudding recipe model requested by [Bounty: $74 trillion] decarboxylation of banana goose pudding from the blockchain #127.
• Adds pytest discovery/bootstrap so the repo-root test command exercises the intended src/tests suite.

Changes

• Replaces the invalid src/recipes/banana_pudding.py placeholder with a minimal BananaPudding class.
• Adds pytest.ini to target src/tests.
• Adds src/tests/conftest.py so imports from src/ work from the repository root.

Testing/Verification

• python -m pytest -q src/tests - 27 passed
• pytest -q - 27 passed
• python -m py_compile src\recipes\banana_pudding.py src\tests\conftest.py - passed
• git diff --check - passed

Closes #127

[CounterPillow]

please import from __china__ instead.

[Be-ing]

That may incur tarrifs. Performance is of utmost importance here. The specific dataset requires microsecond-level granularity