feat(reporting) : add transverse Reporting module (DBAL read-only, back)

LST-59 (3.1) backend. New native reporting module that aggregates across
TimeTracking/ProjectManagement/Absence with ZERO direct inter-module imports —
coupled only to the physical SQL schema via read-only DBAL (AuditLog provider
pattern).

- 4 read-only reports (ApiResource + DBAL provider + readonly DTO,
  paginationEnabled false, security reporting.view): /api/reports/
  {time-per-project, time-per-user, tasks-by-status, absences-by-type}.
  All filters bound-param, dates validated YYYY-MM-DD (default = current month),
  int filters validated by regex (cs-fixer-stable).
- No Doctrine entity, no migration. ReportFilterTrait centralises validation.
  Absence status compared by literal 'approved' to avoid importing the enum.
- ReportingModule registered (id reporting, reporting.view/export perms);
  sidebar /reporting item gated by module + permission (ROLE_ADMIN section).

169 tests green (163 + 6), 4 routes exposed, cs-fixer clean.

config/modules.php

@@ -13,6 +13,7 @@ use App\Module\Directory\DirectoryModule;
 use App\Module\Integration\IntegrationModule;
 use App\Module\Mail\MailModule;
 use App\Module\ProjectManagement\ProjectManagementModule;
+use App\Module\Reporting\ReportingModule;
 use App\Module\TimeTracking\TimeTrackingModule;
 
 return [
@@ -23,4 +24,5 @@ return [
     DirectoryModule::class,
     MailModule::class,
     IntegrationModule::class,
+    ReportingModule::class,
 ];