refactor(mediabunny): [PKG-MB-04] checkpoint typed shim and event cleanup

packages/artplayer-proxy-mediabunny/src/shim-values.ts

@@ -0,0 +1,9 @@
+export function clampVolume(value: unknown): number {
+  return Math.max(0, Math.min(1, Number(value) || 0))
+}
+
+export function timeRanges(duration: number, start: number, end: number): TimeRanges {
+  if (!duration || Number.isNaN(duration) || end <= 0)
+    return { length: 0, start: () => 0, end: () => 0 }
+  return { length: 1, start: () => start, end: () => end }
+}