💄 Fix audio element UI overflow on Firefox

Also added better display when a media bubble src is a variable

Closes #1742

packages/variables/findUniqueVariableValue.ts

@@ -1,12 +1,12 @@
 import { Variable } from './types'
 
-export const findUniqueVariableValue =
+export const findUniqueVariable =
   (variables: Variable[]) =>
-  (value: string | undefined): Variable['value'] => {
+  (value: string | undefined): Variable | null => {
     if (!value || !value.startsWith('{{') || !value.endsWith('}}')) return null
     const variableName = value.slice(2, -2)
     const variable = variables.find(
       (variable) => variable.name === variableName
     )
-    return variable?.value ?? null
+    return variable ?? null
   }