Rewrite VIP tools to not mutate context

src/window.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 pub use about::AboutWindow;
-use egui::{Context, Ui, ViewportBuilder, ViewportId};
+use egui::{Ui, ViewportBuilder, ViewportId};
 pub use game::GameWindow;
 pub use game_screen::DisplayMode;
 pub use gdb::GdbServerWindow;
@@ -32,6 +32,9 @@ pub trait AppWindow {
     fn sim_id(&self) -> SimId {
         SimId::Player1
     }
+    fn image_url(&self, name: &str) -> String {
+        format!("vip://{}/{name}", self.sim_id())
+    }
     fn initial_viewport(&self) -> ViewportBuilder;
     fn show(&mut self, ui: &mut Ui);
     fn on_init(&mut self, args: InitArgs) {
@@ -49,7 +52,6 @@ pub trait AppWindow {
 }
 
 pub struct InitArgs<'a> {
-    pub ctx: &'a Context,
     pub window: &'a Arc<Window>,
     pub render_state: &'a egui_wgpu::RenderState,
 }