feat: refine evidence workflows and local AI positioning

[jb-thery]

feat

• redesign developer use cases as a fixed-height interactive carousel for private specs, P1 incidents, n8n, and document APIs
• make model-agnostic Core positioning and optional offline answer paths consistent across public docs and package metadata
• rebalance full-width animated backgrounds across the landing, including the feature map and footer

fix

• restore focus to the mobile menu trigger after close
• remove the stale release-intelligence section and Dependabot configuration
• keep English and French content, SEO metadata, and generated agent-skill ignores aligned