e6856e6fdf
Port 4000 collides with too many dev tools (Phoenix, GraphQL tools, etc.). Switch to 14242 — unregistered with IANA, no known conflicts, safely within the User Ports range and outside Linux ephemeral port range (32768+). Updates all hardcoded defaults across gateway, web client, CLI commands, playwright config, .env.example, and docs. Bumps @mosaic/cli and @mosaic/mosaic to 0.0.14. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>