refactor: remove 13 dead code artifacts across core/

Dead methods (9):
- Command::bootstrapModuleApp() — unused by all subclasses
- SearchConfig::providerCoverageGaps() — diagnostic method, never called
- RequestInput::queryArray() — no callers
- LocaleResolver::getAvailableLocales() / getDefaultLocale() — unused getters
- EmailVerificationService::getExpiryMinutes() — constant wrapper, never called
- AuthService::loginAndRedirect() — convenience wrapper, never called
- DepartmentService::listForUserAssignments() — no callers
- UserTenantContextService::getAvailableDepartmentsByTenant() — no callers

Dead functions (3):
- navActivePublicPages(), appNormalizeStringList(), appNormalizePositiveIntList()

Dead constant (1):
- PermissionService::API_DOCS_VIEW — duplicated via other paths

Orphaned file (1):
- bin/cli-bootstrap.php — never included anywhere

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/reference-cli-commands.md

@@ -187,5 +187,4 @@ Die `Command`-Basisklasse stellt Helfer bereit:
 | Methode | Zweck |
 |---|---|
 | `$this->bootstrapApp($channel)` | App-Bootstrap fuer Nicht-Modul-Kommandos |
-| `$this->bootstrapModuleApp()` | App-Bootstrap mit Modul-Error-Policy und Locking |
 | `$this->projectRoot()` | Gibt den absoluten Projekt-Root-Pfad zurueck |