- dashboard.html: add onclick handlers for Exportar, date range, chart periods
(week/month/year), Ver todos, quick actions, remove stale inline lead IDs
- admin.js: add exportDashboard(), filterByDateRange(), setChartPeriod(),
initDateRange(), updateChartsWithData() with period slicing, loadAnalytics()
on dashboard init
- login.html: guard /api/auth/me with session cookie check to prevent 401 noise
- server/index.ts: fix Secure cookie flag: only set when HTTPS + production + !localhost