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/units.ts

@@ -0,0 +1,91 @@
+/**
+ *  Most interactions with Ethereum requires integer values, which use
+ *  the smallest magnitude unit.
+ *
+ *  For example, imagine dealing with dollars and cents. Since dollars
+ *  are divisible, non-integer values are possible, such as ``$10.77``.
+ *  By using the smallest indivisible unit (i.e. cents), the value can
+ *  be kept as the integer ``1077``.
+ *
+ *  When receiving decimal input from the user (as a decimal string),
+ *  the value should be converted to an integer and when showing a user
+ *  a value, the integer value should be converted to a decimal string.
+ *
+ *  This creates a clear distinction, between values to be used by code
+ *  (integers) and values used for display logic to users (decimals).
+ *
+ *  The native unit in Ethereum, //ether// is divisible to 18 decimal places,
+ *  where each individual unit is called a //wei//.
+ *
+ *  @_subsection api/utils:Unit Conversion  [about-units]
+ */
+import { assertArgument } from "./errors.js";
+import { FixedNumber } from "./fixednumber.js";
+import { getNumber } from "./maths.js";
+
+import type { BigNumberish, Numeric } from "../utils/index.js";
+
+
+const names = [
+    "wei",
+    "kwei",
+    "mwei",
+    "gwei",
+    "szabo",
+    "finney",
+    "ether",
+];
+
+/**
+ *  Converts %%value%% into a //decimal string//, assuming %%unit%% decimal
+ *  places. The %%unit%% may be the number of decimal places or the name of
+ *  a unit (e.g. ``"gwei"`` for 9 decimal places).
+ *
+ */
+export function formatUnits(value: BigNumberish, unit?: string | Numeric): string {
+    let decimals = 18;
+    if (typeof(unit) === "string") {
+        const index = names.indexOf(unit);
+        assertArgument(index >= 0, "invalid unit", "unit", unit);
+        decimals = 3 * index;
+    } else if (unit != null) {
+        decimals = getNumber(unit, "unit");
+    }
+
+    return FixedNumber.fromValue(value, decimals, { decimals, width: 512 }).toString();
+}
+
+/**
+ *  Converts the //decimal string// %%value%% to a BigInt, assuming
+ *  %%unit%% decimal places. The %%unit%% may the number of decimal places
+ *  or the name of a unit (e.g. ``"gwei"`` for 9 decimal places).
+ */
+export function parseUnits(value: string, unit?: string | Numeric): bigint {
+    assertArgument(typeof(value) === "string", "value must be a string", "value", value);
+
+    let decimals = 18;
+    if (typeof(unit) === "string") {
+        const index = names.indexOf(unit);
+        assertArgument(index >= 0, "invalid unit", "unit", unit);
+        decimals = 3 * index;
+    } else if (unit != null) {
+        decimals = getNumber(unit, "unit");
+    }
+
+    return FixedNumber.fromString(value, { decimals, width: 512 }).value;
+}
+
+/**
+ *  Converts %%value%% into a //decimal string// using 18 decimal places.
+ */
+export function formatEther(wei: BigNumberish): string {
+    return formatUnits(wei, 18);
+}
+
+/**
+ *  Converts the //decimal string// %%ether%% to a BigInt, using 18
+ *  decimal places.
+ */
+export function parseEther(ether: string): bigint {
+    return parseUnits(ether, 18);
+}