Route Z-Image ControlNet diagnostics through logging

[wunianze666-netizen]

Summary

• replace unconditional [DEBUG] / [WARNING] terminal output in z_image_controlnet_extension.py with module logger calls
• add a regression test that checks initialization diagnostics do not write to stdout and still emit logging calls

Why

These diagnostics come from backend/library code and currently print directly to stdout, which can pollute terminal output and make log handling inconsistent for downstream callers.

Validation

• added a regression test for constructor diagnostics behavior
• verified the updated source and test files with py_compile
• ran a source-level regression check to confirm the debug output is no longer implemented with direct print(...) calls

Note

The full pytest dependency set for this repository was not available in the current local environment, so I validated this change with targeted static checks plus compile-time verification.

[Pfannkuchensack]

Good Change.

[lstein]

@wunianze666-netizen
It looks like this PR was submitted without allowing maintainer access, and I don't have permission to update it with the latest base branch changes. Could you either check the "allow edits by maintainers", or rebase your branch and push it back to the PR? If you do the latter, please let me know on Discord ('lstein') so that I can get the PR merged before it goes out of date again.

[lstein]

Superseded by #9298