## Why
An unfamiliar executable can ignore its arguments, so trust in an apparent
inner command must not implicitly trust the executable that runs it.
## What changed
- Evaluate unfamiliar shell executables alongside their parsed commands when
determining unified exec approval requirements. Inner commands can add
restrictions, but cannot grant trust to the executable.
- Include the executable in reusable approval keys so approval for one custom
shell does not apply to another.
- Parse literal PowerShell scripts without launching the requested executable,
preserving command policy checks before approval.
## Testing
Add cross-platform coverage for spoofed shell paths, allowed and forbidden
inner commands, explicit custom-shell approval, and session approval isolation.
GitOrigin-RevId: 0dd2c7e9a2ac30965ef5fe5de1a8d2968bb5f9d0
## What changed
- Add an optional restrictive execution policy to `EnvironmentConfig` and merge it over the active command policy for shell execution and approval decisions.
- Reject environment policies that contain allow rules, so environment configuration can only tighten command access.
- Include the environment policy fingerprint in cached approval keys so policy changes require fresh session approvals.
## Testing
- Cover restrictions overriding saved prefix approvals, policy changes invalidating session approvals, and environment overlays remaining effective when model-specific prefix filtering is active.
GitOrigin-RevId: e94f877549ed5e0f577b8cb52f3c1872c58f029d
## What changed
- Filter saved `allow` prefix rules from the execution policy for cyber-specialized models and models listed in `auto_review.ignore_rules`, while preserving prompt, forbidden, network, and host-executable policy entries.
- Apply the filtered policy consistently to permission instructions, shell commands, unified exec, and the zsh-fork backend.
- Limit cyber-model command approvals to one-time decisions without proposing reusable policy amendments. General models continue to honor saved prefixes, including after switching models within a thread.
## Testing
- Add policy-level coverage for filtering allow-prefix rules while retaining restrictive and network rules.
- Add end-to-end coverage across shell and unified exec paths, zsh-fork execution, user and automatic review, and model switching.
GitOrigin-RevId: f3bd3872424291b12354ec415f33986ec369a368