Release v2.7.0

Features

• Introduce Skills — packaged, reusable instructions the assistant can load on demand via the Linux sandbox, plus a built-in "create-skill" workflow to author your own
• Add Atlas Cloud as a featured provider

Fixes

• Fix text selection in chat list
• Fix heartbeat active hours slider ranges
• Fix heartbeat Linux sandbox running in current conversation
• Fix terminal scroll out of bounds
• Fix OpenAI-compatible model loading when only the default URL is set

Improvements

• Upgrade dependencies
• Update model catalog and scores
• Improve free endpoint DTO sanitization
• Extend API error mapping