Add Radar DC Telegram functionality and configuration

- Introduced new `RadarConfig` structure in `config.go` to manage radar settings, including `statuses_url`, `http_timeout_ms`, and `ping_from`.
- Implemented validation for radar configuration in `config_test.go` to ensure correct URL schemes and timeout limits.
- Added new API routes for radar statuses and ping functionality in the gateway, enhancing the service's capabilities.
- Updated documentation in `GATEWAY_RUN.md` to include details about the new radar features and their usage.
- Enhanced the user interface to include navigation and display options for the Radar DC section in the sidebar and page titles.
- Added client-side API functions for fetching radar statuses and ping responses, improving integration with the frontend.

internal/server/gateway.go

@@ -34,6 +34,9 @@ type Gateway struct {
 	promHandler   http.Handler
 	corsAllowed   []string
 	webUI         http.Handler
+	radarStatusesURL string
+	radarPingFrom    string
+	radarHTTPClient  *http.Client
 }
 
 func writeBadGatewayJSON(w http.ResponseWriter, expose bool, code, message string, upstreamErr error) {
@@ -96,6 +99,21 @@ func NewGateway(p *config.Parsed, log *slog.Logger, geo *geoip.Service) (*Gatewa
 	g.corsAllowed = append([]string(nil), p.Config.CorsAllowedOrigins...)
 	g.agg = aggregate.NewHandler(p, &http.Client{Transport: t}, geo, aggCacheTTL)
 	g.webUI = webui.Handler()
+
+	statusesURL := defaultRadarStatusesURL
+	radarTo := 30 * time.Second
+	if p.Config.Radar != nil {
+		if u := strings.TrimSpace(p.Config.Radar.StatusesURL); u != "" {
+			statusesURL = u
+		}
+		if p.Config.Radar.HTTPTimeoutMs > 0 {
+			radarTo = time.Duration(p.Config.Radar.HTTPTimeoutMs) * time.Millisecond
+		}
+		g.radarPingFrom = strings.TrimSpace(p.Config.Radar.PingFrom)
+	}
+	g.radarStatusesURL = statusesURL
+	g.radarHTTPClient = &http.Client{Transport: t, Timeout: radarTo}
+
 	return g, nil
 }
 
@@ -242,6 +260,13 @@ func routeEndpoint(path string) string {
 	if path == "/api/agg" {
 		return "agg"
 	}
+	if strings.HasPrefix(path, "/api/radar/") {
+		rest := strings.TrimPrefix(path, "/api/radar/")
+		if rest == "" {
+			return "radar"
+		}
+		return "radar_" + strings.ReplaceAll(rest, "/", "_")
+	}
 	if strings.HasPrefix(path, "/api/live/events") {
 		return "live_events"
 	}
@@ -291,6 +316,10 @@ func (g *Gateway) serve(w http.ResponseWriter, r *http.Request) {
 		g.serveLiveEvents(w, r)
 		return
 	}
+	if r.URL.Path == "/api/radar/statuses" || r.URL.Path == "/api/radar/ping-dc" {
+		g.serveRadar(w, r)
+		return
+	}
 	if !strings.HasPrefix(r.URL.Path, prefix) {
 		g.webUI.ServeHTTP(w, r)
 		return