Settings shell now owns only personal user preferences (appearance,
language, layout, AI assistant). All 14 admin/tenant/ops leaves
converted to controlled redirects pointing at their canonical owners
(Administration, Setup, Ops). Language merged into user-preferences.
Identity-providers rehomed from settings to administration as
canonical owner. Navigation config updated. 22 new route tests added.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
