Add risk disclaimer section in all three languages (EN/ZH/JA) warning
users about potential GitHub ToS violations, account suspension risks,
and no long-term availability guarantee for the Copilot reverse proxy.
Update CHANGELOG.md with full v3.12.3 entry, create release notes in
three languages (en/zh/ja), bump macOS minimumSystemVersion from 10.15
to 12.0 (Monterey) to match actual runtime requirements, and update
README version badges and links.
Create a local backup under ~/.cc-switch/skill-backups/ before removing
skill directories. The backup includes all skill files and a meta.json
with original skill metadata. Old backups are pruned to keep at most 20.
The backup path is returned to the frontend and shown in the success
toast. Bump version to 3.12.3.
