Add omics runtime skill pack

[zongtingwei]

Summary

This PR adds a curated omics runtime skill pack for BioClaw and updates the repository README files to clarify the skills contribution path.

Included runtime skills:

• scrna-preprocessing-clustering
• cell-annotation
• chip-seq
• atac-seq
• differential-expression
• proteomics
• metagenomics
• structural-biology

Each runtime skill is placed under container/skills/<skill-name>/ with a flat layout that matches the current container sync behavior:

• SKILL.md
• technical_reference.md
• commands_and_thresholds.md

This PR also updates README.md and README.zh-CN.md to state that new BioClaw-compatible skills should first be contributed to Bioclaw_Skills_Hub, and that validated skills may later be promoted into the main BioClaw repository.

Notes

• The installer skill remains at .claude/skills/add-omics-runtime-pack/SKILL.md
• The eight runtime skill folders live under container/skills/
• The README updates are limited to contribution-path messaging in the project header area

[zongtingwei]

Closing this PR because it was opened from the wrong branch and includes unrelated runtime-skill-pack changes. A clean README-only replacement has been opened as #28.