Phase 3 Step 7: Scan Comparison Features & UX Improvements

Implemented comprehensive scan comparison functionality with historical
analysis and improved user experience for scan triggering.

Features Added:
- Scan comparison engine with ports, services, and certificates analysis
- Drift score calculation (0.0-1.0 scale) for infrastructure changes
- Side-by-side comparison UI with color-coded changes (added/removed/changed)
- Historical trend charts showing port counts over time
- "Compare with Previous" button on scan detail pages
- Scan history API endpoint for trending data

API Endpoints:
- GET /api/scans/<id1>/compare/<id2> - Compare two scans
- GET /api/stats/scan-history/<id> - Historical scan data for charts

UI Improvements:
- Replaced config file text inputs with dropdown selectors
- Added config file selection to dashboard and scans pages
- Improved delete scan confirmation with proper async handling
- Enhanced error messages with detailed validation feedback
- Added 2-second delay before redirect to ensure deletion completes

Comparison Features:
- Port changes: tracks added, removed, and unchanged ports
- Service changes: detects version updates and service modifications
- Certificate changes: monitors SSL/TLS certificate updates
- Interactive historical charts with clickable data points
- Automatic detection of previous scan for comparison

Bug Fixes:
- Fixed scan deletion UI alert appearing on successful deletion
- Prevented config file path duplication (configs/configs/...)
- Improved error handling for failed API responses
- Added proper JSON response parsing with fallback handling

Testing:
- Created comprehensive test suite for comparison functionality
- Tests cover comparison API, service methods, and drift scoring
- Added edge case tests for identical scans and missing data

docker-compose-web.yml

@@ -44,7 +44,7 @@ services:
     # Health check to ensure web service is running
     healthcheck:
       test: ["CMD", "python3", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:5000/api/settings/health').read()"]
-      interval: 30s
+      interval: 60s
       timeout: 10s
       retries: 3
       start_period: 40s