Fix map centering to use calculated origin

Backend Changes:
- Added OriginConfig struct to server package
- Modified NewServer to accept origin configuration
- Added /api/origin endpoint to serve origin data to frontend
- Updated main.go to pass origin configuration to server

Frontend Changes:
- Modified initializeMap() to fetch origin from API before map creation
- Updated initializeCoverageMap() to also use origin data
- Added fallback coordinates in case API request fails
- Maps now center on the calculated origin position instead of hardcoded coordinates

The map now properly centers on the calculated average position of enabled
sources (or manually configured origin), providing a much better user experience
with appropriate regional view.

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

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

internal/assets/static/js/app.js

@@ -100,8 +100,19 @@ class SkyView {
     }
 
     // Map Initialization
-    initializeMap() {
+    async initializeMap() {
-        this.map = L.map('map').setView([51.4700, -0.4600], 10);
+        // Get origin from server
+        let origin = { latitude: 51.4700, longitude: -0.4600 }; // fallback
+        try {
+            const response = await fetch('/api/origin');
+            if (response.ok) {
+                origin = await response.json();
+            }
+        } catch (error) {
+            console.warn('Could not fetch origin, using default:', error);
+        }
+        
+        this.map = L.map('map').setView([origin.latitude, origin.longitude], 10);
         
         // Dark tile layer
         L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
@@ -117,9 +128,20 @@ class SkyView {
         document.getElementById('toggle-sources').addEventListener('click', () => this.toggleSources());
     }
 
-    initializeCoverageMap() {
+    async initializeCoverageMap() {
         if (!this.coverageMap) {
-            this.coverageMap = L.map('coverage-map').setView([51.4700, -0.4600], 10);
+            // Get origin from server
+            let origin = { latitude: 51.4700, longitude: -0.4600 }; // fallback
+            try {
+                const response = await fetch('/api/origin');
+                if (response.ok) {
+                    origin = await response.json();
+                }
+            } catch (error) {
+                console.warn('Could not fetch origin for coverage map, using default:', error);
+            }
+            
+            this.coverageMap = L.map('coverage-map').setView([origin.latitude, origin.longitude], 10);
             
             L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
                 attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'

internal/server/server.go

@@ -18,12 +18,20 @@ import (
 	"skyview/internal/merger"
 )
 
+// OriginConfig represents the reference point configuration
+type OriginConfig struct {
+	Latitude  float64 `json:"latitude"`
+	Longitude float64 `json:"longitude"`
+	Name      string  `json:"name,omitempty"`
+}
+
 // Server handles HTTP requests and WebSocket connections
 type Server struct {
 	port        int
 	merger      *merger.Merger
 	staticFiles embed.FS
 	server      *http.Server
+	origin      OriginConfig
 	
 	// WebSocket management
 	wsClients   map[*websocket.Conn]bool
@@ -50,11 +58,12 @@ type AircraftUpdate struct {
 }
 
 // NewServer creates a new HTTP server
-func NewServer(port int, merger *merger.Merger, staticFiles embed.FS) *Server {
+func NewServer(port int, merger *merger.Merger, staticFiles embed.FS, origin OriginConfig) *Server {
 	return &Server{
 		port:          port,
 		merger:        merger,
 		staticFiles:   staticFiles,
+		origin:        origin,
 		wsClients:     make(map[*websocket.Conn]bool),
 		upgrader: websocket.Upgrader{
 			CheckOrigin: func(r *http.Request) bool {
@@ -107,6 +116,7 @@ func (s *Server) setupRoutes() http.Handler {
 	api.HandleFunc("/aircraft/{icao}", s.handleGetAircraftDetails).Methods("GET")
 	api.HandleFunc("/sources", s.handleGetSources).Methods("GET")
 	api.HandleFunc("/stats", s.handleGetStats).Methods("GET")
+	api.HandleFunc("/origin", s.handleGetOrigin).Methods("GET")
 	api.HandleFunc("/coverage/{sourceId}", s.handleGetCoverage).Methods("GET")
 	api.HandleFunc("/heatmap/{sourceId}", s.handleGetHeatmap).Methods("GET")
 	
@@ -180,6 +190,11 @@ func (s *Server) handleGetStats(w http.ResponseWriter, r *http.Request) {
 	json.NewEncoder(w).Encode(stats)
 }
 
+func (s *Server) handleGetOrigin(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(s.origin)
+}
+
 func (s *Server) handleGetCoverage(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	sourceID := vars["sourceId"]

static/js/app.js

@@ -100,8 +100,19 @@ class SkyView {
     }
 
     // Map Initialization
-    initializeMap() {
+    async initializeMap() {
-        this.map = L.map('map').setView([51.4700, -0.4600], 10);
+        // Get origin from server
+        let origin = { latitude: 51.4700, longitude: -0.4600 }; // fallback
+        try {
+            const response = await fetch('/api/origin');
+            if (response.ok) {
+                origin = await response.json();
+            }
+        } catch (error) {
+            console.warn('Could not fetch origin, using default:', error);
+        }
+        
+        this.map = L.map('map').setView([origin.latitude, origin.longitude], 10);
         
         // Dark tile layer
         L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
@@ -117,9 +128,20 @@ class SkyView {
         document.getElementById('toggle-sources').addEventListener('click', () => this.toggleSources());
     }
 
-    initializeCoverageMap() {
+    async initializeCoverageMap() {
         if (!this.coverageMap) {
-            this.coverageMap = L.map('coverage-map').setView([51.4700, -0.4600], 10);
+            // Get origin from server
+            let origin = { latitude: 51.4700, longitude: -0.4600 }; // fallback
+            try {
+                const response = await fetch('/api/origin');
+                if (response.ok) {
+                    origin = await response.json();
+                }
+            } catch (error) {
+                console.warn('Could not fetch origin for coverage map, using default:', error);
+            }
+            
+            this.coverageMap = L.map('coverage-map').setView([origin.latitude, origin.longitude], 10);
             
             L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
                 attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'