/**
 * Strip self-referential reasoning-fence delimiters that a provider leaks
 * *inside* a structured thinking part.
 *
 * The visible-channel healers ({@link ../utils/leaked-thinking-stream},
 * {@link ./fenced-thinking}) split leaked ` ```thinking ` fences out of the
 * *text* stream. They never run over parts a provider already flags as
 * thinking, so when a model (observed on Gemini thought summaries — issue
 * #8719) emits a bare ` ```thinking ` / ` ``````thinking ` opener line between
 * summaries, that delimiter reaches display and persistence verbatim as fence
 * spam inside the reasoning block.
 *
 * This stripper removes only a *standalone* reasoning-fence opener line — a line
 * that is nothing but a run of ≥3 backticks immediately followed by the info
 * string `thinking` or `reasoning`. Such a line is always redundant inside an
 * already-structured thinking block and never carries content. Inline mentions
 * (prose on the same line), language-tagged code fences (` ```rs `), and bare
 * closers (` ``` `) are left untouched so legitimate fenced code inside the
 * reasoning survives.
 *
 * Streaming-safe: deltas may split a line anywhere. A trailing partial line is
 * held only while it remains a viable opener prefix; the moment it cannot be an
 * opener it is flushed and the rest of the line passes through character-level.
 * Correctness never depends on the prefix heuristic — every held line is
 * classified strictly on its newline (or on {@link ThinkingFenceStripper.flush})
 * before it is dropped.
 */
/**
 * Stateful, line-oriented stripper for leaked reasoning-fence openers in one
 * structured thinking block. One instance per thinking block; feed every
 * thinking delta through {@link push} and drain the tail with {@link flush}.
 */
export declare class ThinkingFenceStripper {
    #private;
    /** Consume one thinking delta; returns the sanitized text to emit (may be empty). */
    push(chunk: string): string;
    /** Drain any held partial line at block end; returns text to emit (may be empty). */
    flush(): string;
}