v1.6.1: Rename to JetBriefCheck

Changes

• Rename project to JetBriefCheck throughout (code, config, CI, docs, skill metadata)
• Update report footer: Generated by JetBriefCheck v1.6.1 (2026-02-25) · Rules current as of 2026-02-17
• Move ZIP to release assets instead of tracking in repo (eliminates push races from automated ZIP rebuilds)
• Fix pre-existing test failures (version 1.5.0 → 1.6.0 mismatch)

Migration

• Re-deploy skill: python deploy_skill.py (new skill path: ~/.claude/skills/jetbriefcheck/)