## Why
Shell quoting can hide credentials from raw-text checks, and startup files can restore real credentials after the broker replaces them with dummy values.
## What changed
- Decode shell literals without evaluating them and reject snapshots containing credentials in executable source, including aliases, functions, and heredocs.
- Preserve credential policy overrides, explicit unsets, and aliases whose source variables were removed. Support credential aliases in Zsh tied arrays while rejecting credentials that span array elements.
- Guard snapshot replay against credential restoration through shell startup files and preserve unrelated `ENV` settings.
- Apply Windows environment-key casing rules to credential overrides, suppress unredacted sandbox diagnostics during snapshot capture, and clear inherited environment variables before launching escalated commands.
## Testing
Add regression coverage for shell quoting and escaped credentials, Zsh tied arrays, startup-file replay, readonly credentials, policy overrides, and sensitive capture timeout and cancellation handling.
GitOrigin-RevId: 58274c07c715423241d26ce6dd2c2b4230cf0f64
Winston Howes
ec512d2347