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/providers/signer-noncemanager.ts

@@ -0,0 +1,98 @@
+import { defineProperties } from "../utils/index.js";
+import { AbstractSigner } from "./abstract-signer.js";
+
+import type { TypedDataDomain, TypedDataField } from "../hash/index.js";
+
+import type {
+    BlockTag, Provider, TransactionRequest, TransactionResponse
+} from "./provider.js";
+import type { Signer } from "./signer.js";
+
+
+/**
+ *  A **NonceManager** wraps another [[Signer]] and automatically manages
+ *  the nonce, ensuring serialized and sequential nonces are used during
+ *  transaction.
+ */
+export class NonceManager extends AbstractSigner {
+    /**
+     *  The Signer being managed.
+     */
+    signer!: Signer;
+
+    #noncePromise: null | Promise<number>;
+    #delta: number;
+
+    /**
+     *  Creates a new **NonceManager** to manage %%signer%%.
+     */
+    constructor(signer: Signer) {
+        super(signer.provider);
+        defineProperties<NonceManager>(this, { signer });
+
+        this.#noncePromise = null;
+        this.#delta = 0;
+    }
+
+    async getAddress(): Promise<string> {
+        return this.signer.getAddress();
+    }
+
+    connect(provider: null | Provider): NonceManager {
+        return new NonceManager(this.signer.connect(provider));
+    }
+
+    async getNonce(blockTag?: BlockTag): Promise<number> {
+        if (blockTag === "pending") {
+            if (this.#noncePromise == null) {
+                this.#noncePromise = super.getNonce("pending");
+            }
+
+            const delta = this.#delta;
+            return (await this.#noncePromise) + delta;
+        }
+
+        return super.getNonce(blockTag);
+    }
+
+    /**
+     *  Manually increment the nonce. This may be useful when managng
+     *  offline transactions.
+     */
+    increment(): void {
+        this.#delta++;
+    }
+
+    /**
+     *  Resets the nonce, causing the **NonceManager** to reload the current
+     *  nonce from the blockchain on the next transaction.
+     */
+    reset(): void {
+        this.#delta = 0;
+        this.#noncePromise = null;
+    }
+
+    async sendTransaction(tx: TransactionRequest): Promise<TransactionResponse> {
+        const noncePromise = this.getNonce("pending");
+        this.increment();
+
+        tx = await this.signer.populateTransaction(tx);
+        tx.nonce = await noncePromise;
+
+        // @TODO: Maybe handle interesting/recoverable errors?
+        // Like don't increment if the tx was certainly not sent
+        return await this.signer.sendTransaction(tx);
+    }
+
+    signTransaction(tx: TransactionRequest): Promise<string> {
+        return this.signer.signTransaction(tx);
+    }
+
+    signMessage(message: string | Uint8Array): Promise<string> {
+        return this.signer.signMessage(message);
+    }
+
+    signTypedData(domain: TypedDataDomain, types: Record<string, Array<TypedDataField>>, value: Record<string, any>): Promise<string> {
+        return this.signer.signTypedData(domain, types, value);
+    }
+}