init: add source code from src.zip

src/hooks/useTerminalSize.ts

@@ -0,0 +1,15 @@
+import { useContext } from 'react'
+import {
+  type TerminalSize,
+  TerminalSizeContext,
+} from 'src/ink/components/TerminalSizeContext.js'
+
+export function useTerminalSize(): TerminalSize {
+  const size = useContext(TerminalSizeContext)
+
+  if (!size) {
+    throw new Error('useTerminalSize must be used within an Ink App component')
+  }
+
+  return size
+}