Migrate from file-based configs to database with per-IP site configuration

Major architectural changes:
   - Replace YAML config files with database-stored ScanConfig model
   - Remove CIDR block support in favor of individual IP addresses per site
   - Each IP now has its own expected_ping, expected_tcp_ports, expected_udp_ports
   - AlertRule now uses config_id FK instead of config_file string

   API changes:
   - POST /api/scans now requires config_id instead of config_file
   - Alert rules API uses config_id with validation
   - All config dropdowns fetch from /api/configs dynamically

   Template updates:
   - scans.html, dashboard.html, alert_rules.html load configs via API
   - Display format: Config Title (X sites) in dropdowns
   - Removed Jinja2 config_files loops

   Migrations:
   - 008: Expand CIDRs to individual IPs with per-IP port configs
   - 009: Remove CIDR-related columns
   - 010: Add config_id to alert_rules, remove config_file

app/web/services/config_service.py

@@ -129,7 +129,7 @@ class ConfigService:
                 'id': site.id,
                 'name': site.name,
                 'description': site.description,
-                'cidr_count': len(site.cidrs)
+                'ip_count': len(site.ips)
             })
 
         return {