## Why
The core item tests still had a cluster of plan-mode `Op::UserTurn`
literals that used `SandboxPolicy::DangerFullAccess` and omitted
`permission_profile`. These tests are validating emitted item lifecycle
events, so keeping them on the legacy sandbox-only turn shape adds noise
to the broader permissions migration without testing legacy behavior.
## What Changed
- Adds a local `disabled_plan_turn()` helper that preserves the existing
`std::env::current_dir()` turn cwd behavior.
- Uses `turn_permission_fields(PermissionProfile::Disabled, cwd)` to
populate both the compatibility `sandbox_policy` and canonical
`permission_profile` fields.
- Replaces the plan-mode hand-built turns in
`codex-rs/core/tests/suite/items.rs`, removing all `SandboxPolicy`
references from that file and reducing remaining `codex-rs/core/tests`
`SandboxPolicy` files from 16 to 15.
## Verification
- `cargo check -p codex-core --tests`