Previous regex used a greedy [^|]* and required at least one / before
the host, so 'curl roboco-orchestrator:8000/api' (no scheme, no slash)
slipped through. Split into two simpler checks: (a) line starts with
curl/wget/http/https/httpie, AND (b) line contains a forbidden host.
Probe-verified: scheme-ful, scheme-less, and protocol-relative forms
all denied; external URLs still allowed; GitHub-specific deny still
fires first.
Prompts told agents internal API calls were denied; the guard only
denied GitHub. Combined with task 4 (X-Agent-Role enforcement) this
closes the manifest-bypass loophole.