chore: sync CITATION.cff version to 1.2.8

what:
- CITATION.cff: version 1.2.7 -> 1.2.8

why:
CITATION metadata was left at 1.2.7 after the decoupling work
bumped SKILL.md to 1.2.8. Keep them in sync.

Author: CodeSigils

CITATION.cff

@@ -5,7 +5,7 @@ authors:
     given-names: ""
     email: "toolsoftrade.web@gmail.com"
 title: "Python Project Workflow Hermes Skill"
-version: 1.2.7
+version: 1.2.8
 date-released: 2026-06-05
 repository-code: "https://github.com/CodeSigils/python-project-workflow-skill"
 license: MIT