feat(taskbuffer): add sliding-window rate limiting and result-sharing to TaskConstraintGroup and integrate with TaskManager

ts/taskbuffer.interfaces.ts

@@ -1,12 +1,21 @@
 import type { ITaskStep } from './taskbuffer.classes.taskstep.js';
 import type { Task } from './taskbuffer.classes.task.js';
 
+export interface IRateLimitConfig {
+  maxPerWindow: number;  // max completions allowed within the sliding window
+  windowMs: number;      // sliding window duration in ms
+}
+
+export type TResultSharingMode = 'none' | 'share-latest';
+
 export interface ITaskConstraintGroupOptions<TData extends Record<string, unknown> = Record<string, unknown>> {
   name: string;
   constraintKeyForExecution: (task: Task<any, any, TData>, input?: any) => string | null | undefined;
   maxConcurrent?: number;  // default: Infinity
   cooldownMs?: number;     // default: 0
   shouldExecute?: (task: Task<any, any, TData>, input?: any) => boolean | Promise<boolean>;
+  rateLimit?: IRateLimitConfig;
+  resultSharingMode?: TResultSharingMode;  // default: 'none'
 }
 
 export interface ITaskExecution<TData extends Record<string, unknown> = Record<string, unknown>> {