feat: add Asciinema terminal recording server stack

Added new asciinema stack for self-hosted terminal recording and sharing
platform with custom "Pivoine" theme inspired by pivoine.art aesthetic.

New Services:
- **asciinema**: Terminal recording server at asciinema.pivoine.art
  - PostgreSQL backend for recording persistence
  - Email authentication via IONOS SMTP magic links
  - Public/private recording visibility controls
  - Embed recordings on any website
  - Custom rose/magenta themed UI

Custom Theme (asciinema/theme/custom.css):
- Primary color: RGB(206, 39, 91) - Deep rose/magenta
- Dark charcoal backgrounds: HSL(0, 0%, 17.5%)
- High contrast design with bold color accents
- Styled components: navigation, cards, forms, buttons, terminal player
- Smooth animations and hover effects
- Responsive design with mobile breakpoints
- Custom scrollbars, selection colors, loading states

Infrastructure Updates:
- PostgreSQL: Added `asciinema` database to init script
- arty.yml: Added ASCIINEMA_* environment variables
- compose.yaml: Included asciinema stack in root composition
- CLAUDE.md: Comprehensive documentation with CLI setup guide
- Backup: Added asciinema-backup plan (11 AM daily, 7d/4w/6m/2y retention)

Configuration:
- URL: https://asciinema.pivoine.art
- Database: PostgreSQL `asciinema` database
- SMTP: Email auth via IONOS SMTP
- Unclaimed TTL: 30 days (auto-cleanup)
- Secret: Generated 64-char hex key in .env

Features:
- Record terminal sessions with asciinema CLI
- Web player with play/pause controls and speed adjustment
- User profiles with personal recording collections
- Embed recordings via iframe or direct links
- Privacy controls (public/private recordings)
- Automatic cleanup of unclaimed recordings

Integration Points:
- Documentation: Embed terminal demos
- Blog posts: Share command-line tutorials
- GitHub: Link recordings in README files
- Tutorials: Interactive terminal walkthroughs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

arty.yml

@@ -180,6 +180,15 @@ envs:
     AI_VECTOR_DB: pgvector
     AI_CRAWL4AI_PORT: 11235
     AI_OPENAI_API_BASE_URLS: https://api.anthropic.com/v1
+    # Asciinema
+    ASCIINEMA_TRAEFIK_ENABLED: true
+    ASCIINEMA_COMPOSE_PROJECT_NAME: asciinema
+    ASCIINEMA_IMAGE: ghcr.io/asciinema/asciinema-server:latest
+    ASCIINEMA_TRAEFIK_HOST: asciinema.pivoine.art
+    ASCIINEMA_DB_NAME: asciinema
+    ASCIINEMA_UNCLAIMED_TTL: 30
+    ASCIINEMA_MAIL_FROM: noreply@pivoine.art
+    ASCIINEMA_MAIL_REPLY_TO: valknar@pivoine.art
     # Watchtower
     WATCHTOWER_POLL_INTERVAL: 300
     WATCHTOWER_LABEL_ENABLE: true