core tests: build user turns from permission profiles (#20011)

## Summary
- Add `turn_permission_fields()` so tests that construct `Op::UserTurn`
directly can provide a canonical `PermissionProfile` while still filling
the required legacy `sandbox_policy` compatibility field.
- Migrate direct user-turn construction in core integration tests from
`SandboxPolicy::DangerFullAccess` to `PermissionProfile::Disabled`.
- Continue reducing direct `SandboxPolicy` usage in
`codex-rs/core/tests`, from 41 files after #20010 to 32 files in this
PR.

## Testing
- `cargo check -p codex-core --tests`
- `just fmt`
- `just fix -p core_test_support`
- `just fix -p codex-core`

codex-rs/core/tests/suite/json_result.rs

@@ -1,14 +1,15 @@
 #![cfg(not(target_os = "windows"))]
 
+use codex_protocol::models::PermissionProfile;
 use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::EventMsg;
 use codex_protocol::protocol::Op;
-use codex_protocol::protocol::SandboxPolicy;
 use codex_protocol::user_input::UserInput;
 use core_test_support::responses;
 use core_test_support::skip_if_no_network;
 use core_test_support::test_codex::TestCodex;
 use core_test_support::test_codex::test_codex;
+use core_test_support::test_codex::turn_permission_fields;
 use core_test_support::wait_for_event;
 use pretty_assertions::assert_eq;
 use responses::ev_assistant_message;
@@ -69,6 +70,8 @@ async fn codex_returns_json_result(model: String) -> anyhow::Result<()> {
     responses::mount_sse_once_match(&server, match_json_text_param, sse1).await;
 
     let TestCodex { codex, cwd, .. } = test_codex().build(&server).await?;
+    let (sandbox_policy, permission_profile) =
+        turn_permission_fields(PermissionProfile::Disabled, cwd.path());
 
     // 1) Normal user input – should hit server once.
     codex
@@ -82,8 +85,8 @@ async fn codex_returns_json_result(model: String) -> anyhow::Result<()> {
             cwd: cwd.path().to_path_buf(),
             approval_policy: AskForApproval::Never,
             approvals_reviewer: None,
-            sandbox_policy: SandboxPolicy::DangerFullAccess,
-            permission_profile: None,
+            sandbox_policy,
+            permission_profile,
             model,
             effort: None,
             summary: None,