feat(attic): Add JWT authentication and client configuration for bina…

[danielkosgei]

…ry cache

• Install both attic-server and attic-client packages via nix
• Generate base64-encoded JWT secret (minimum 32 bytes) for server authentication
• Replace attic.toml template with inline configuration to ensure proper secret injection
• Add attic client configuration for both narvana and root users with generated JWT tokens
• Implement JWT token generation with 10-year expiry for worker service authentication
• Create narvana cache and verify accessibility after server startup
• Add health check loop to wait for Attic server to be ready before configuration
• Store ATTIC_TOKEN in control-plane.env for worker service consumption
• Update directory permissions: root:root for storage, narvana:narvana for config
• Improve logging messages to reflect both server and client installation steps