docs: add v1.1.0 changelog and update README with Protection features ...

- CHANGELOG: document styled error pages, per-FC maintenance mode, dynamic
  preview, Envoy NACK fix, theme variable fixes, and Owl MCP updates
- README: add Protection & Maintenance and Per-Domain Maintenance via Owl
  feature cards to the features table

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Initial release — Aegis v1.0.0 ...

Self-hosted Envoy gateway with AI threat analysis, TLS automation,
and real-time security dashboard.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>