feat(web): rationalize settings IA into personal-preferences shell with admin rehoming [SPRINT-026]

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>

docs/modules/ui/TASKS.md

@@ -5,6 +5,7 @@
 - [DONE] `docs/implplan/SPRINT_20260308_015_FE_orphan_filter_bar_unification.md` - Initial FilterBarComponent adoption batch; audit-log-table and trust-audit-log were later rolled back in sprint `024` to restore lost semantics.
 - [DONE] `docs-archived/implplan/SPRINT_20260308_024_FE_orphan_revival_regression_remediation.md` - Fixed reviewed orphan-revival regressions: build blockers cleared, canonical evidence-thread navigation restored, audit/trust filter capabilities restored, and fabricated finding evidence removed from mounted hosts.
 - [DOING] `docs/implplan/SPRINT_20260308_025_FE_safe_cleanup_and_generated_artifacts_prune.md` - Approved UI cleanup to prune committed generated/debug artifacts plus confirmed orphan route and legacy release-control leaves.
+- [DONE] `docs/implplan/SPRINT_20260308_026_FE_settings_information_architecture_rationalization.md` - Settings IA rationalized: personal-preferences shell with admin/ops rehoming via controlled redirects.
 
 ## Queued Sprint Links
 - `docs/modules/ui/orphan-revival-batch/README.md` - review index for the orphan shared-component and disconnected-route revival batch.
@@ -175,3 +176,11 @@
 - [DONE] FE-SPL-002 Derive the canonical list-detail shell
 - [DONE] FE-SPL-003 Adopt the consolidated shell on bounded mounted surfaces
 - [DONE] FE-SPL-004 Verify and document the consolidation
+- [DONE] FE-SETIA-001 Audit and classify every settings route
+- [DONE] FE-SETIA-002 Freeze the target IA and backward-compatibility contract
+- [DONE] FE-SETIA-003 Build the personal-settings shell and navigation model
+- [DONE] FE-SETIA-004 Merge overlapping personal preference leaves
+- [DONE] FE-SETIA-005 Rehome admin, tenant, and operations configuration leaves
+- [DONE] FE-SETIA-006 Remove or collapse wrapper and alias-only settings pages
+- [DONE] FE-SETIA-007 Add focused route, nav, and UX regression coverage
+- [DONE] FE-SETIA-008 Sync docs and ship the IA decision

docs/modules/ui/implementation_plan.md

@@ -7,6 +7,7 @@ Provide a living plan for UI deliverables, dependencies, and evidence.
 - Track current sprints under `docs/implplan/SPRINT_*.md` for this module.
 - Update this file when new scoped work is approved.
 - Sprint `025` is active for safe cleanup of approved dead leaves and committed generated/debug artifacts in the Web workspace.
+- Sprint `026` shipped Settings IA rationalization: the Settings shell now owns only personal preferences (appearance, language, layout, AI assistant). All admin, tenant, and operations configuration leaves redirect to their canonical owners (Administration, Setup, Ops). See `docs/features/checked/web/settings-ia-rationalization-ui.md`.
 
 ## Near-term deliverables
 - No active UI deliverables are currently staged in `docs/implplan`.