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/routes/main.py

@@ -35,20 +35,7 @@ def dashboard():
     Returns:
         Rendered dashboard template
     """
-    import os
-
-    # Get list of available config files
-    configs_dir = '/app/configs'
-    config_files = []
-
-    try:
-        if os.path.exists(configs_dir):
-            config_files = [f for f in os.listdir(configs_dir) if f.endswith(('.yaml', '.yml'))]
-            config_files.sort()
-    except Exception as e:
-        logger.error(f"Error listing config files: {e}")
-
-    return render_template('dashboard.html', config_files=config_files)
+    return render_template('dashboard.html')
 
 
 @bp.route('/scans')
@@ -60,20 +47,7 @@ def scans():
     Returns:
         Rendered scans list template
     """
-    import os
-
-    # Get list of available config files
-    configs_dir = '/app/configs'
-    config_files = []
-
-    try:
-        if os.path.exists(configs_dir):
-            config_files = [f for f in os.listdir(configs_dir) if f.endswith(('.yaml', '.yml'))]
-            config_files.sort()
-    except Exception as e:
-        logger.error(f"Error listing config files: {e}")
-
-    return render_template('scans.html', config_files=config_files)
+    return render_template('scans.html')
 
 
 @bp.route('/scans/<int:scan_id>')
@@ -299,7 +273,6 @@ def alert_rules():
     Returns:
         Rendered alert rules template
     """
-    import os
     from flask import current_app
     from web.models import AlertRule
 
@@ -317,19 +290,7 @@ def alert_rules():
     if rules is None:
         rules = []
 
-    # Get list of available config files
-    configs_dir = '/app/configs'
-    config_files = []
-
-    try:
-        if os.path.exists(configs_dir):
-            config_files = [f for f in os.listdir(configs_dir) if f.endswith(('.yaml', '.yml'))]
-            config_files.sort()
-    except Exception as e:
-        logger.error(f"Error listing config files: {e}")
-
     return render_template(
         'alert_rules.html',
-        rules=rules,
-        config_files=config_files
+        rules=rules
     )