Most users register against the production hub, so requiring --hub on
every invocation was friction. Default the flag to https://riahub.ai
via a module-level DEFAULT_HUB_URL constant; explicit --hub still wins,
so dev and self-hosted setups (e.g. http://whitehorse:3005) keep working.
The legacy `ria-agent run` path keeps its own --hub handling unchanged
— it has a config-file fallback and existing operators rely on it.
Bumps version to 0.1.8.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Covers the User-Agent / Cloudflare fix, request timeout, structured
error reasons, human-readable default agent names, and updated CLI
help text for the per-user `ria_reg_*` registration key flow.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
