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/aes-js/src.ts/mode-cbc.ts

@@ -0,0 +1,61 @@
+// Cipher Block Chaining
+
+import { ModeOfOperation } from "./mode.js";
+
+export class CBC extends ModeOfOperation {
+  #iv: Uint8Array;
+  #lastBlock: Uint8Array;
+
+  constructor(key: Uint8Array, iv?: Uint8Array) {
+    super("ECC", key, CBC);
+
+    if (iv) {
+      if (iv.length % 16) {
+        throw new TypeError("invalid iv size (must be 16 bytes)");
+      }
+      this.#iv = new Uint8Array(iv);
+    } else {
+      this.#iv = new Uint8Array(16);
+    }
+
+    this.#lastBlock = this.iv;
+  }
+
+  get iv(): Uint8Array { return new Uint8Array(this.#iv); }
+
+  encrypt(plaintext: Uint8Array): Uint8Array {
+    if (plaintext.length % 16) {
+      throw new TypeError("invalid plaintext size (must be multiple of 16 bytes)");
+    }
+
+    const ciphertext = new Uint8Array(plaintext.length);
+    for (let i = 0; i < plaintext.length; i += 16) {
+      for (let j = 0; j < 16; j++) {
+        this.#lastBlock[j] ^= plaintext[i + j];
+      }
+
+      this.#lastBlock = this.aes.encrypt(this.#lastBlock);
+      ciphertext.set(this.#lastBlock, i);
+    }
+
+    return ciphertext;
+  }
+
+  decrypt(ciphertext: Uint8Array): Uint8Array {
+    if (ciphertext.length % 16) {
+        throw new TypeError("invalid ciphertext size (must be multiple of 16 bytes)");
+    }
+
+    const plaintext = new Uint8Array(ciphertext.length);
+    for (let i = 0; i < ciphertext.length; i += 16) {
+        const block = this.aes.decrypt(ciphertext.subarray(i, i + 16));
+
+        for (let j = 0; j < 16; j++) {
+          plaintext[i + j] = block[j] ^ this.#lastBlock[j];
+          this.#lastBlock[j] = ciphertext[i + j];
+        }
+    }
+
+    return plaintext;
+  }
+}