/**
 * botmux callback-button ownership marker.
 *
 * WHY: botmux reply/session/config cards carry callback buttons (🔊 语音总结 /
 * 关闭会话 / 重启 / 配置 …). When another bot reads such a card (history /
 * cross-bot relay / quote), a plain-text flattening renders them as
 * `[🔊 语音总结]` chrome it can never click — prompt pollution. The parser
 * strips any button it can PROVE is botmux's own callback; proof must not
 * depend on a hand-maintained action wordlist, because every new botmux
 * button added later would silently leak again until someone updates the list.
 *
 * HOW: every card botmux sends is stamped at the single egress choke point
 * (client.ts send/reply/ephemeral/update — all interactive traffic flows
 * through those four). Each `tag:'button'` gets a `__bm_cb:1` marker on its
 * callback payload — both real payload shapes: legacy top-level `value` and
 * v2 `behaviors:[{type:'callback', value}]`. Jump buttons (open_url) are left
 * unmarked so their URLs keep surfacing in flattened text.
 *
 * The marker round-trips to card-handler on click as an unknown key and is
 * ignored there; it is additive only. Cards sent by older botmux builds have
 * no marker — the parser's legacy action wordlist covers those.
 */
export declare const BOTMUX_CALLBACK_MARKER_KEY = "__bm_cb";
/**
 * Stamp every callback button in an interactive card's JSON. Idempotent and
 * total: on any JSON anomaly the input string is returned unchanged (a stamp
 * failure must never block an outbound message). Non-interactive content
 * should not be passed here at all (callers gate on msgType === 'interactive'),
 * but a non-card JSON body is tolerated harmlessly.
 */
export declare function stampBotmuxCallbackMarkers(cardJson: string): string;
/** True when `el` is a button stamped by stampBotmuxCallbackMarkers. */
export declare function hasBotmuxCallbackMarker(el: any): boolean;
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