Implement pipeio

Implement pipeio.smk_log module — standardized Snakemake script logging. Reference impl: pixecog:code/utils/smk/smk_logging.py (imported by 43 pipeline scripts as from utils.smk.smk_logging import ...). Needs to be an importable runtime module (not MCP tool). See issue-arash-20260326-185435 for full spec. Once landed, pixecog scripts can be migrated from utils.smk.smk_logging to pipeio.smk_log.

Related Notes

• issue-arash-20260326-185435-586786.md — Direct parent spec for this implementation task — the full spec for pipeio.smk_log is in this issue
• issue-arash-20260326-185507-424521.md — Related pipeio absorption work; smk_log migration is part of the same pipeio consolidation effort
• issue-arash-20260326-232713-565171.md — Closes the module_context→pipeio issue, contextually related to pipeio feature landing decisions