Force JS eval of window.location

We need to get the fqdn of machine running the app, otherwise the
frontend cannot access the api on the VOC VM

frontend/Cargo.lock

@@ -1410,6 +1410,7 @@ dependencies = [
  "env_logger",
  "ewebsock",
  "hrtime",
+ "js-sys",
  "log",
  "serde",
  "serde_json",

frontend/Cargo.toml

@@ -10,6 +10,7 @@ eframe = { version = "0.27.0", default-features = false, features = [
     "default_fonts", # Embed the default egui fonts.
     "glow",          # Use the glow rendering backend. Alternative: "wgpu".
 ] }
+js-sys = "0.3.69"
 log = "0.4"
 serde = { version = "1", features = ["derive"] }
 hrtime = "0.2.0"

frontend/src/app.rs

@@ -7,6 +7,7 @@ use std::{
 use egui::{Button, Color32, RichText, Rounding, Sense, Stroke, Vec2};
 use ewebsock::{Options, WsReceiver, WsSender};
 use wasm_timer::Instant;
+use js_sys::eval;
 
 use crate::websocket::{
     AddHyperdeckRequest, ClientRequest, HyperdeckConnectionState, HyperdeckRecordBay,
@@ -27,8 +28,12 @@ pub struct HyperdeckMonitorApp {
 
 impl Default for HyperdeckMonitorApp {
     fn default() -> Self {
+        // returns voc.emf.camp:9681/
+        let window_location = eval("window.location.host").unwrap().as_string().unwrap();
+        // returns ws://voc.emf.camp:9681
+        let api_websocket_location = format!("ws://{}ws", window_location);
         let (ws_sender, ws_receiver) =
-            ewebsock::connect("ws://127.0.0.1:9681/ws", Options::default()).unwrap();
+            ewebsock::connect(api_websocket_location, Options::default()).unwrap();
         Self {
             blink: false,
             last_blink_change: Instant::now(),