Clean up and optimize codebase for production readiness

Performance & Reliability Improvements:
- Increase WebSocket buffer sizes from 1KB to 8KB for better throughput
- Increase broadcast channel buffer from 100 to 1000 messages
- Increase Beast message channel buffer from 1000 to 5000 messages
- Increase connection timeout from 10s to 30s for remote receivers

Code Quality Improvements:
- Remove debug output from production code (CPR Debug, Merger Update spam)
- Add MaxDistance constant to replace magic number (999999)
- Clean up comments for better maintainability
- Implement auto-enable for selected aircraft trails

Benefits:
- Much cleaner server logs without debug spam
- Better performance under high aircraft density
- More reliable WebSocket connections with larger buffers
- Improved fault tolerance with increased timeouts

🤖 Generated with [Claude Code](https://claude.ai/code)

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

assets/static/js/app.js

@@ -191,11 +191,18 @@ class SkyView {
             // Update selected aircraft
             this.selectedAircraft = icao;
             
-            // Show trail for newly selected aircraft if enabled
-            if (this.selectedTrailEnabled) {
-                this.aircraftManager.showAircraftTrail(icao);
+            // Automatically enable selected aircraft trail when an aircraft is selected
+            if (!this.selectedTrailEnabled) {
+                this.selectedTrailEnabled = true;
+                const selectedTrailCheckbox = document.getElementById('show-selected-trail');
+                if (selectedTrailCheckbox) {
+                    selectedTrailCheckbox.checked = true;
+                }
             }
             
+            // Show trail for newly selected aircraft
+            this.aircraftManager.showAircraftTrail(icao);
+            
             // DON'T change map view - just open popup like Leaflet expects
             if (this.mapManager.map && aircraft.Latitude && aircraft.Longitude) {
                 const marker = this.aircraftManager.aircraftMarkers.get(icao);