Move documentation to docs/ directory and improve terminology

- Move ARCHITECTURE.md and CLAUDE.md to docs/ directory
- Replace "real-time" terminology with accurate "low-latency" and "high-performance"
- Update README to reflect correct performance characteristics
- Add comprehensive ICAO country database with SQLite backend
- Fix display options positioning and functionality
- Add map scale controls and improved range ring visibility
- Enhance aircraft marker orientation and trail management

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

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

assets/static/js/app.js

@@ -22,6 +22,10 @@ class SkyView {
         // Charts
         this.charts = {};
         
+        // Selected aircraft tracking
+        this.selectedAircraft = null;
+        this.selectedTrailEnabled = false;
+        
         this.init();
     }
 
@@ -40,6 +44,11 @@ class SkyView {
             // Initialize aircraft manager with the map
             this.aircraftManager = new AircraftManager(map);
             
+            // Set up selected aircraft trail callback
+            this.aircraftManager.setSelectedAircraftCallback((icao) => {
+                return this.selectedTrailEnabled && this.selectedAircraft === icao;
+            });
+            
             // Initialize WebSocket with callbacks
             this.wsManager = new WebSocketManager(
                 (message) => this.handleWebSocketMessage(message),
@@ -71,11 +80,12 @@ class SkyView {
         const centerMapBtn = document.getElementById('center-map');
         const resetMapBtn = document.getElementById('reset-map');
         const toggleTrailsBtn = document.getElementById('toggle-trails');
-        const toggleRangeBtn = document.getElementById('toggle-range');
         const toggleSourcesBtn = document.getElementById('toggle-sources');
         
         if (centerMapBtn) {
-            centerMapBtn.addEventListener('click', () => this.aircraftManager.centerMapOnAircraft());
+            centerMapBtn.addEventListener('click', () => {
+                this.aircraftManager.centerMapOnAircraft(() => this.mapManager.getSourcePositions());
+            });
         }
         
         if (resetMapBtn) {
@@ -89,12 +99,6 @@ class SkyView {
             });
         }
         
-        if (toggleRangeBtn) {
-            toggleRangeBtn.addEventListener('click', () => {
-                const showRange = this.mapManager.toggleRangeCircles();
-                toggleRangeBtn.textContent = showRange ? 'Hide Range' : 'Show Range';
-            });
-        }
         
         if (toggleSourcesBtn) {
             toggleSourcesBtn.addEventListener('click', () => {
@@ -128,6 +132,50 @@ class SkyView {
                 this.mapManager.updateCoverageDisplay();
             });
         }
+        
+        // Display option checkboxes
+        const sitePositionsCheckbox = document.getElementById('show-site-positions');
+        const rangeRingsCheckbox = document.getElementById('show-range-rings');
+        const selectedTrailCheckbox = document.getElementById('show-selected-trail');
+        
+        if (sitePositionsCheckbox) {
+            sitePositionsCheckbox.addEventListener('change', (e) => {
+                if (e.target.checked) {
+                    this.mapManager.showSources = true;
+                    this.mapManager.updateSourceMarkers();
+                } else {
+                    this.mapManager.showSources = false;
+                    this.mapManager.sourceMarkers.forEach(marker => this.mapManager.map.removeLayer(marker));
+                    this.mapManager.sourceMarkers.clear();
+                }
+            });
+        }
+        
+        if (rangeRingsCheckbox) {
+            rangeRingsCheckbox.addEventListener('change', (e) => {
+                if (e.target.checked) {
+                    this.mapManager.showRange = true;
+                    this.mapManager.updateRangeCircles();
+                } else {
+                    this.mapManager.showRange = false;
+                    this.mapManager.rangeCircles.forEach(circle => this.mapManager.map.removeLayer(circle));
+                    this.mapManager.rangeCircles.clear();
+                }
+            });
+        }
+        
+        if (selectedTrailCheckbox) {
+            selectedTrailCheckbox.addEventListener('change', (e) => {
+                this.selectedTrailEnabled = e.target.checked;
+                if (!e.target.checked && this.selectedAircraft) {
+                    // Hide currently selected aircraft trail
+                    this.aircraftManager.hideAircraftTrail(this.selectedAircraft);
+                } else if (e.target.checked && this.selectedAircraft) {
+                    // Show currently selected aircraft trail
+                    this.aircraftManager.showAircraftTrail(this.selectedAircraft);
+                }
+            });
+        }
     }
 
     setupAircraftSelection() {
@@ -135,6 +183,19 @@ class SkyView {
             const { icao, aircraft } = e.detail;
             this.uiManager.switchView('map-view');
             
+            // Hide trail for previously selected aircraft
+            if (this.selectedAircraft && this.selectedTrailEnabled) {
+                this.aircraftManager.hideAircraftTrail(this.selectedAircraft);
+            }
+            
+            // Update selected aircraft
+            this.selectedAircraft = icao;
+            
+            // Show trail for newly selected aircraft if enabled
+            if (this.selectedTrailEnabled) {
+                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);
@@ -171,6 +232,11 @@ class SkyView {
         this.uiManager.updateStatistics();
         this.uiManager.updateHeaderInfo();
         
+        // Clear selected aircraft if it no longer exists
+        if (this.selectedAircraft && !this.aircraftManager.aircraftData.has(this.selectedAircraft)) {
+            this.selectedAircraft = null;
+        }
+        
         // Update coverage controls
         this.mapManager.updateCoverageControls();