export declare function getShellConfig(): {
    shell: string;
    args: string[];
};
export declare function detectRuntimeShell(): string | undefined;
export declare function sanitizeBinaryOutput(text: string): string;
export declare function killProcessTree(pid: number): void;
/**
 * Undo a `powershell -Command "…"` wrapper the caller did not need.
 *
 * On Windows `exec` ALREADY runs the command in PowerShell (see
 * getShellConfig). A command that wraps itself in another one therefore runs
 * nested — and the outer shell parses the double-quoted argument FIRST, which
 * means it expands every `$name` in it before the inner shell ever sees it.
 * Undefined outer variables expand to nothing, so the inner script silently
 * loses its variables:
 *
 *     sent by the koi:  foreach ($d in @('a','b')) { … }
 *     PowerShell ran:   foreach ( in @('a','b')) { … }
 *         →  "Missing variable name after foreach"
 *
 *     sent by the koi:  @{n='L';e={$_.Line.Trim()}}
 *     PowerShell ran:   @{n='L';e={.Line.Trim()}}
 *         →  "An expression was expected after '('"
 *
 * Traced on the owner's machine 2026-08-17: five failures in one session, all
 * of them this, all of them looking like the model writing bad PowerShell when
 * the script it wrote was correct. Unwrapping is strictly better than the
 * nested run in every case — same shell, same script, one less parse.
 */
export declare function unwrapNestedPowerShell(command: string): string;
/**
 * Drop a `2>&1` redirection that PowerShell turns into a failure.
 *
 * In Windows PowerShell, redirecting a NATIVE command's stderr into the
 * pipeline wraps every stderr line in a NativeCommandError ErrorRecord and
 * makes the whole pipeline exit non-zero — even when the program succeeded.
 * Measured here with a program that prints to both streams and exits 0:
 *
 *     node -e "console.error(1);console.log(2)" 2>&1 | Out-String
 *         → exit 1, stdout polluted with "node : 1 / At line:1 char:1 / + ..."
 *     same command without the 2>&1
 *         → exit 0, stdout "2"
 *
 * That is what turned a passing `pnpm test 2>&1 | Out-String` into
 * "tools.exec failed: node.exe : $ tsx --import ./tests/test-env.ts ...".
 * The test suite was fine; the shell editorialised.
 *
 * Removing it loses nothing: exec captures stderr separately and reports both
 * streams already, which is the reason to merge them in the first place.
 */
export declare function dropPowerShellStderrMerge(command: string): {
    command: string;
    changed: boolean;
};
/**
 * Is this command "throw a URL at the user's default browser"?
 *
 * `Start-Process https://…` on Windows, `open https://…` on macOS,
 * `xdg-open` on Linux, `cmd /c start https://…`. All of them put a page on
 * screen and hand back nothing: no DOM, no elements, no way to click. A koi
 * that reaches for one has given up on the task while appearing to do it.
 *
 * Deliberately narrow. It matches only a launcher whose argument is a URL, so
 * `Start-Process notepad`, `open ./report.pdf` and `git open` are untouched —
 * opening a FILE for someone is a real thing to want.
 */
export declare function isShellOpenUrl(command: string): boolean;