[FIX] Deploy fixes - Auth header passthrough, dashboard query, landing page

- Add Authorization header passthrough in .htaccess for PHP-FPM
- Remove invalid 'severity' column query from DashboardController
- Add landing page (index.html) with feature overview

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

application/controllers/DashboardController.php

@@ -36,14 +36,6 @@ class DashboardController extends BaseController
         );
 
         // Rischi aperti
-        $openRisks = Database::fetchAll(
-            'SELECT severity, COUNT(*) as count
-             FROM risks
-             WHERE organization_id = ? AND status NOT IN ("closed")
-             GROUP BY FIELD(severity, "critical", "high", "medium", "low") -- non supportato, usiamo ORDER',
-            [$orgId]
-        );
-
         $riskCounts = Database::fetchOne(
             'SELECT
                 SUM(CASE WHEN inherent_risk_score >= 20 THEN 1 ELSE 0 END) as critical_high,