feat(reporting) : add Reporting dashboard front layer
LST-59 (3.1) front. Completes the Reporting module.
- New frontend/modules/reporting/ layer (auto-detected): /reporting page
(admin middleware) consuming the 4 read-only report endpoints.
- Filters (period presets + custom dates, project, user). 4 sections (time per
project, time per user, tasks by status, absences by type) each with a
DataTable + a Chart.js chart (reused global registration).
- Front-side CSV export per section (useCsvExport: BOM UTF-8, ; separator).
- i18n keys (reporting.*, sidebar.admin.reporting).
nuxt build passes; /reporting routed; no route regression.
Matthieu
f4ffc02028