[FEAT] Add EmailService, RateLimitService, ReportService + integrations

Services:
- EmailService: CSIRT notifications (24h/72h/30d), training alerts, welcome email
- RateLimitService: File-based rate limiting for auth and AI endpoints
- ReportService: Executive HTML report, CSV exports (risks/incidents/controls/assets)

Integrations:
- AuthController: Rate limiting on login (5/min, 20/h) and register (3/10min)
- IncidentController: Email notifications on CSIRT milestones
- AuditController: Executive report and CSV export endpoints
- Router: 429 rate limit error handling, new audit export routes

Database:
- Migration 002: email_log table for notification tracking

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

docs/sql/002_email_log.sql

@@ -0,0 +1,17 @@
+-- ═══════════════════════════════════════════════════════════════════════════
+-- NIS2 Agile - Migration 002: Email Log
+-- ═══════════════════════════════════════════════════════════════════════════
+
+USE nis2_agile_db;
+
+CREATE TABLE IF NOT EXISTS email_log (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    recipient VARCHAR(255) NOT NULL,
+    subject VARCHAR(500) NOT NULL,
+    type VARCHAR(100),
+    status ENUM('sent','failed') DEFAULT 'sent',
+    error_message TEXT,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    INDEX idx_recipient (recipient),
+    INDEX idx_created (created_at)
+) ENGINE=InnoDB;