Fix debug screen regression (#3300)

[ci no changelog needed]

Entry points links were not clickable if an empty entry name was provided, like `http://localhost:8080?entry=`

The reason was the loader div that covered the whole screen.

app/ide-desktop/lib/content/src/index.ts

@@ -949,12 +949,15 @@ async function runEntryPoint(config: Config) {
         let fn_name = wasm_entry_point_pfx + entryTarget
         let fn = wasm[fn_name]
         if (fn) {
+            // Loader will be removed by IDE after its initialization.
+            // All other code paths need to call `loader.destroy()`.
             fn()
         } else {
             loader.destroy()
             show_debug_screen(wasm, "Unknown entry point '" + entryTarget + "'. ")
         }
     } else {
+        loader.destroy()
         show_debug_screen(wasm, '')
     }
 }