chore: Enforce a few house rules via eslint (#2539)

tests/card-controller/call/tones/custom.test.ts

@@ -10,13 +10,13 @@ interface AudioMocks {
 }
 
 // Uses real jsdom HTMLAudioElement instances and only stubs the parts jsdom
-// can't fulfil (`play()` / `pause()` — no audio backend). Tests then exercise
-// observable behaviour: registered listeners fire via `dispatchEvent`,
-// property writes round-trip on the element, etc.
+// can't fulfil (`play()` / `pause()` -- no audio backend). Tests then exercise
+// observable behaviour: registered listeners fire via `dispatchEvent`, property
+// writes round-trip on the element, etc.
 //
 // Called once at module load. The `beforeEach`/`afterEach` calls inside this
-// helper register Vitest hooks at the file level — Vitest picks them up just
-// as if they had been written at the top of the file — so every test in the
+// helper register Vitest hooks at the file level -- Vitest picks them up just
+// as if they had been written at the top of the file -- so every test in the
 // file gets fresh mocks installed/torn down automatically.
 const useAudioElementMocks = (): AudioMocks => {
   const handle = { instances: [] as HTMLAudioElement[] } as AudioMocks;