bug(admin/settings): 'permission denied: requires view on config' toast still showing for non-admin users on Purchasing Policies (regression after #979/PR #981) #1413

Repro

1. Log in as a Standard user (or other non-admin role with view access to settings).
2. Navigate to Admin > Purchasing Policies.
3. Observe the bottom of the page.

Expected

No 'permission denied' error message is shown. The page degrades gracefully: visible sections are shown, and the hidden Exchange Automation section is simply not rendered (no error banner for it).

Actual

The message 'Failed to load settings: permission denied: requires view on config' appears at the bottom of the page.

Context

Issue #979 and PR #981 were filed to suppress this banner for non-admin users. The fix merged 2026-06-09. The banner has reappeared (regression), or the fix did not cover all non-admin role scenarios.

Note: This is distinct from issue #1410 (fields being editable). Even if fields are properly disabled, the error banner should not show.

Sheet reference

Bugs and improvement suggestions tab, row 553. Standard User Role tab, row 7.2.