/**
 * Boolean when-expressions for extension UI contributions (Phase 2).
 * Grammar: expression := term (('&&' | '||') term)*; term := '!' term | atom;
 * atom := variable (('==' | '!=') literal)? | '(' expression ')'
 */
export type WhenContext = Record<string, unknown>;
/**
 * Evaluate a when-expression string against a flat context object.
 * Unknown variables are treated as falsey for boolean tests; missing keys are undefined.
 */
export declare function evaluateWhenExpression(expr: string, ctx: WhenContext): boolean;