Selected profile cannot relax a root `approval_policy = "never"`

Summary

scanApprovalPolicy() does not use the same selected-profile precedence as the other effective Codex settings.

Model, reasoning effort, and provider resolution all prefer an explicitly configured value in the selected profile over the root value. Approval policy instead computes:

return config["approval_policy"] === "never" ||
  selectedScanProfile(config)?.["approval_policy"] === "never"
  ? "never"
  : "on-request";

If the root config says approval_policy = "never" and the selected profile explicitly says approval_policy = "on-request", this returns "never" rather than the selected profile's value.

Impact

This is not display-only. The resolved value is passed to codex.startThread({ approvalPolicy }), written into the scan recipe/preflight configuration, and projected into scanRuntimeCodexConfig().

A selected profile therefore cannot restore on-request approvals when the root config is more restrictive, even though profile-specific model/provider settings already override their root counterparts.

Expected behavior

If the selected profile has its own approval_policy, resolve that value first. Otherwise fall back to the root setting. Codex Security only needs to distinguish the supported never and on-request outcomes.

Suggested fix

Mirror scanModelProvider()/scanModelConfiguration() precedence for approval_policy, and add regression cases for both directions:

• root never, selected profile on-request -> on-request;
• root on-request, selected profile never -> never.

Locate scanApprovalPolicy(), then compare its precedence with scanModelProvider() and scanModelConfiguration(). Add regression coverage for both root/selected-profile approval_policy combinations: root never with selected on-request, and root on-request with selected never. Confirm the resolved value remains consistent through codex.startThread({ approvalPolicy }), scan recipe/preflight configuration, and scanRuntimeCodexConfig().