refactor(system-info): reduce to Stripe-style status page

Reduce admin/system-info to a single focused status view: overall
status banner, components list from existing health checks, and an
environment meta table. Drops the Modules and Permissions tabs —
those were dev-diagnostics already available via CLI.

- Remove SystemInfoService + its test; wire the action directly to
  SystemHealthService and build meta inline
- Extend SystemHealthService with per-check label + description so
  the UI speaks in customer terms while the CLI doctor path stays
  compatible
- Rebuild the view on existing app-stats-table + app-empty-state
  primitives; add a small app-status-banner component for the
  headline signal
- Align help-center nav label and i18n keys (de/en)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

phpstan-baseline.neon

@@ -1159,10 +1159,16 @@ parameters:
 			path: core/Service/Stats/AdminStatsViewDataService.php
 
 		-
-			message: '#^Public method "MintyPHP\\Service\\System\\SystemInfoService\:\:buildPageData\(\)" is never used$#'
+			message: '#^Public method "MintyPHP\\Service\\System\\SystemHealthService\:\:runAll\(\)" is never used$#'
 			identifier: public.method.unused
 			count: 1
-			path: core/Service/System/SystemInfoService.php
+			path: core/Service/System/SystemHealthService.php
+
+		-
+			message: '#^Public property "MintyPHP\\App\\Module\\ModuleManifest\:\:\$enabledByDefault" is never used$#'
+			identifier: public.property.unused
+			count: 1
+			path: core/App/Module/ModuleManifest.php
 
 		-
 			message: '#^Public method "MintyPHP\\Service\\Tenant\\TenantAvatarService\:\:hasAvatar\(\)" is never used$#'