Add ONVIF probe detector via unicast WS-Discovery

- Add ProbeONVIF() prober: sends unicast WS-Discovery to ip:3702,
  parses XAddrs, Name, Hardware from response (no auth needed)
- Add ONVIFResult struct to probe models
- Register ONVIF detector with highest priority (before HomeKit)
- Fix homekit.html back-wrapper max-width to match design system

internal/probe/probe.go

@@ -33,6 +33,14 @@ func Init() {
 	}
 
 	ports = loadPorts()
+	// ONVIF detector (highest priority -- auto-discovers all streams)
+	detectors = append(detectors, func(r *probe.Response) string {
+		if r.Probes.ONVIF != nil {
+			return "onvif"
+		}
+		return ""
+	})
+
 	// HomeKit detector
 	detectors = append(detectors, func(r *probe.Response) string {
 		if r.Probes.MDNS != nil {
@@ -115,6 +123,12 @@ func runProbe(parent context.Context, ip string) *probe.Response {
 		resp.Probes.HTTP = r
 		mu.Unlock()
 	})
+	run(func() {
+		r, _ := probe.ProbeONVIF(fastCtx, ip)
+		mu.Lock()
+		resp.Probes.ONVIF = r
+		mu.Unlock()
+	})
 
 	wg.Wait()