## What changed
- Discover configured provider credentials in child environment values even when canonical credential variables are absent. Match complete tokens while preserving regex word boundaries and avoiding ambiguous or overlapping provider matches.
- Replace and restore credentials by their original spans, preserving adjacent tokens and generated dummy aliases across destination rebinding. Reject dummy values that embed another provider's credentials.
- Extend text virtualization and provider source checks to configured credentials, including short credentials with distinctive prefixes, while preserving operational paths.
- Expose trusted provider metadata and active bindings through `CredentialBrokerEnvironment`, and remove marked configured credential variables when stripping the managed proxy environment.
## Testing
Add regression tests for alias discovery, regex boundaries and alternatives, overlapping and adjacent credentials, destination rebinding, dummy restoration, disallowed credential sources, and operational path preservation.
GitOrigin-RevId: dd85c595ce9550fbfdb07ef296a23e458ca165dd
5a9aec40a5