/**
 * Copy the given text to the system clipboard.
 *
 * Uses the modern async Clipboard API when available, falling back to the legacy
 * `document.execCommand('copy')` approach for non-secure (`http://`) contexts where
 * `navigator.clipboard` is unavailable, and for secure-context cases where `writeText()`
 * itself rejects (no user activation, unfocused document, Permissions Policy denial).
 * Throws if both paths fail.
 *
 * Adapted from the (unmaintained) `clipboard-copy` package by Feross Aboukhadijeh,
 * https://github.com/feross/clipboard-copy - MIT licensed.
 *
 * TODO: consider dropping the execCommand fallback?
 */
export declare function copyToClipboard(text: string): Promise<void>;