docs: add logoscore testing gotchas to create-logos-module skill

[jimmy-claw]

Documents four real gotchas discovered while building logos-kv-module:

1. QStringList not supported by logoscore — use QString JSON instead
2. Empty string args dropped silently — workaround with single-arg variants
3. Do not call registerObject() in initLogos — logos_host subprocess mode handles this; direct call causes segfault
4. Nix sandbox temp dirs — /tmp read-only, ctest spawns per-process static counters collide; fix with PID+counter and env var

All four discovered via trial and error building logos-kv-module.