feat(cli): expose contributor-check and credential-audit as pip CLI commands (#1711)

Add agt-contributor-check and agt-credential-audit as console_scripts
entry points in the agent-governance-toolkit package. This allows
consumers to pip install instead of cloning the repo to access these
tools.

Addresses: github/awesome-copilot#1520 review feedback.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: imran-siddique

agent-governance-python/agent-compliance/pyproject.toml

@@ -67,3 +67,5 @@ agent-governance-toolkit = "agent_compliance.cli.main:main"
 agent-governance = "agent_compliance.cli.main:main"
 agent-compliance = "agent_compliance.cli.main:main"
 agt = "agent_compliance.cli.agt:main"
+agt-contributor-check = "agent_compliance.cli.contributor_check:_entry"
+agt-credential-audit = "agent_compliance.cli.credential_audit:_entry"