/**
 * UNC under the win family: two leading separators, a host, a share — either separator, as `path.win32`
 * reads it. The ONE UNC recognizer behind `isAbsoluteForFamily`, `pathIdentityOf` and `joinForFamily`
 * (tools/fs/safety.ts), the symlink-chain reader (core/path-identity.ts) and the engine's own chain walk
 * (engine/execution-env/symlink-chain.ts).
 *
 * A pure spelling test with no dependency, so the engine layer and the tools layer both read it from here:
 * the engine never imports tools/, and tools reach the engine only through the `internal/harness` facade.
 */
export declare function isUncSpelling(p: string): boolean;