refactor: move brother_node development artifact to dev/test-nodes subdirectory

Development Artifact Cleanup:
✅ BROTHER_NODE REORGANIZATION: Moved development test node to appropriate location
- dev/test-nodes/brother_node/: Moved from root directory for better organization
- Contains development configuration, test logs, and test chain data
- No impact on production systems - purely development/testing artifact

✅ DEVELOPMENT ARTIFACTS IDENTIFIED:
- Chain ID: aitbc-brother-chain (test/development chain)
- Ports: 8010 (P2P) and 8011 (RPC) - different from production
- Environment: .env file with test configuration
- Logs: rpc.log and node.log from development testing session (March 15, 2026)

✅ ROOT DIRECTORY CLEANUP: Removed development clutter from production directory
- brother_node/ moved to dev/test-nodes/brother_node/
- Root directory now contains only production-ready components
- Development artifacts properly organized in dev/ subdirectory

DIRECTORY STRUCTURE IMPROVEMENT:
📁 dev/test-nodes/: Development and testing node configurations
🏗️ Root Directory: Clean production structure with only essential components
🧪 Development Isolation: Test environments separated from production

BENEFITS:
✅ Clean Production Directory: No development artifacts in root
✅ Better Organization: Development nodes grouped in dev/ subdirectory
✅ Clear Separation: Production vs development environments clearly distinguished
✅ Maintainability: Easier to identify and manage development components

RESULT: Successfully moved brother_node development artifact to dev/test-nodes/ subdirectory, cleaning up the root directory while preserving development testing environment for future use.

dev/env/node_modules/ethers/src.ts/utils/events.ts

@@ -0,0 +1,105 @@
+/**
+ *  Events allow for applications to use the observer pattern, which
+ *  allows subscribing and publishing events, outside the normal
+ *  execution paths.
+ *
+ *  @_section api/utils/events:Events  [about-events]
+ */
+import { defineProperties } from "./properties.js";
+
+/**
+ *  A callback function called when a an event is triggered.
+ */
+export type Listener = (...args: Array<any>) => void;
+
+/**
+ *  An **EventEmitterable** behaves similar to an EventEmitter
+ *  except provides async access to its methods.
+ *
+ *  An EventEmitter implements the observer pattern.
+ */
+export interface EventEmitterable<T> {
+    /**
+     *  Registers a %%listener%% that is called whenever the
+     *  %%event%% occurs until unregistered.
+     */
+    on(event: T, listener: Listener): Promise<this>;
+
+    /**
+     *  Registers a %%listener%% that is called the next time
+     *  %%event%% occurs.
+     */
+    once(event: T, listener: Listener): Promise<this>;
+
+    /**
+     *  Triggers each listener for %%event%% with the %%args%%.
+     */
+    emit(event: T, ...args: Array<any>): Promise<boolean>;
+
+    /**
+     *  Resolves to the number of listeners for %%event%%.
+     */
+    listenerCount(event?: T): Promise<number>;
+
+    /**
+     *  Resolves to the listeners for %%event%%.
+     */
+    listeners(event?: T): Promise<Array<Listener>>;
+
+    /**
+     *  Unregister the %%listener%% for %%event%%. If %%listener%%
+     *  is unspecified, all listeners are unregistered.
+     */
+    off(event: T, listener?: Listener): Promise<this>;
+
+    /**
+     *  Unregister all listeners for %%event%%.
+     */
+    removeAllListeners(event?: T): Promise<this>;
+
+    /**
+     *  Alias for [[on]].
+     */
+    addListener(event: T, listener: Listener): Promise<this>;
+
+    /**
+     *  Alias for [[off]].
+     */
+    removeListener(event: T, listener: Listener): Promise<this>;
+}
+
+/**
+ *  When an [[EventEmitterable]] triggers a [[Listener]], the
+ *  callback always ahas one additional argument passed, which is
+ *  an **EventPayload**.
+ */
+export class EventPayload<T> {
+    /**
+     *  The event filter.
+     */
+    readonly filter!: T;
+
+    /**
+     *  The **EventEmitterable**.
+     */
+    readonly emitter!: EventEmitterable<T>;
+
+    readonly #listener: null | Listener;
+
+    /**
+     *  Create a new **EventPayload** for %%emitter%% with
+     *  the %%listener%% and for %%filter%%.
+     */
+    constructor(emitter: EventEmitterable<T>, listener: null | Listener, filter: T) {
+        this.#listener = listener;
+        defineProperties<EventPayload<any>>(this, { emitter, filter });
+    }
+
+    /**
+     *  Unregister the triggered listener for future events.
+     */
+    async removeListener(): Promise<void> {
+        if (this.#listener == null) { return; }
+        await this.emitter.off(this.filter, this.#listener);
+    }
+}