Initial commit: modern React video player library

Add all source files for a feature-rich, reusable video player built with React, TypeScript, and Vite. Includes core components, context, hooks, utilities, styles, demo app, and configuration files.

src/components/controls/PIPButton.tsx

@@ -0,0 +1,26 @@
+import React from 'react'
+import { usePlayerContext } from '../../contexts/PlayerContext'
+import { PIPIcon } from '../../icons'
+import './ControlButton.css'
+
+export const PIPButton: React.FC = () => {
+  const { videoState, togglePictureInPicture } = usePlayerContext()
+
+  // Check if PIP is supported
+  const isPIPSupported = 'pictureInPictureEnabled' in document
+
+  if (!isPIPSupported) {
+    return null
+  }
+
+  return (
+    <button
+      className="control-button pip-button"
+      onClick={togglePictureInPicture}
+      aria-label={videoState.pictureInPicture ? 'Exit picture-in-picture' : 'Enter picture-in-picture'}
+      title="Picture-in-picture (P)"
+    >
+      <PIPIcon size={24} color="var(--player-text)" />
+    </button>
+  )
+}