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/crypto/signature.ts

@@ -0,0 +1,410 @@
+
+import { ZeroHash } from "../constants/index.js";
+import {
+    concat, dataLength, getBigInt, getBytes, getNumber, hexlify,
+    toBeArray, isHexString, zeroPadValue,
+    assertArgument, assertPrivate
+} from "../utils/index.js";
+
+import type {
+    BigNumberish, BytesLike, Numeric
+} from "../utils/index.js";
+
+
+// Constants
+const BN_0 = BigInt(0);
+const BN_1 = BigInt(1);
+const BN_2 = BigInt(2);
+const BN_27 = BigInt(27);
+const BN_28 = BigInt(28);
+const BN_35 = BigInt(35);
+const BN_N = BigInt("0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141");
+const BN_N_2 = BN_N / BN_2; // Must be integer (floor) division; do NOT shifts
+
+const inspect = Symbol.for("nodejs.util.inspect.custom");
+
+const _guard = { };
+
+// @TODO: Allow Uint8Array
+
+/**
+ *  A SignatureLike
+ *
+ *  @_docloc: api/crypto:Signing
+ */
+export type SignatureLike = Signature | string | {
+    r: string;
+    s: string;
+    v: BigNumberish;
+    yParity?: 0 | 1;
+    yParityAndS?: string;
+} | {
+    r: string;
+    yParityAndS: string;
+    yParity?: 0 | 1;
+    s?: string;
+    v?: number;
+} | {
+    r: string;
+    s: string;
+    yParity: 0 | 1;
+    v?: BigNumberish;
+    yParityAndS?: string;
+};
+
+function toUint256(value: BigNumberish): string {
+    return zeroPadValue(toBeArray(value), 32);
+}
+
+/**
+ *  A Signature  @TODO
+ *
+ *
+ *  @_docloc: api/crypto:Signing
+ */
+export class Signature {
+    #r: string;
+    #s: string;
+    #v: 27 | 28;
+    #networkV: null | bigint;
+
+    /**
+     *  The ``r`` value for a signature.
+     *
+     *  This represents the ``x`` coordinate of a "reference" or
+     *  challenge point, from which the ``y`` can be computed.
+     */
+    get r(): string { return this.#r; }
+    set r(value: BytesLike) {
+        assertArgument(dataLength(value) === 32, "invalid r", "value", value);
+        this.#r = hexlify(value);
+    }
+
+    /**
+     *  The ``s`` value for a signature.
+     */
+    get s(): string {
+        assertArgument(parseInt(this.#s.substring(0, 3)) < 8, "non-canonical s; use ._s", "s", this.#s);
+        return this.#s;
+    }
+    set s(_value: BytesLike) {
+        assertArgument(dataLength(_value) === 32, "invalid s", "value", _value);
+        this.#s = hexlify(_value);
+    }
+
+    /**
+     *  Return the s value, unchecked for EIP-2 compliance.
+     *
+     *  This should generally not be used and is for situations where
+     *  a non-canonical S value might be relevant, such as Frontier blocks
+     *  that were mined prior to EIP-2 or invalid Authorization List
+     *  signatures.
+     */
+    get _s(): string { return this.#s; }
+
+    /**
+     *  Returns true if the Signature is valid for [[link-eip-2]] signatures.
+     */
+    isValid(): boolean {
+        const s = BigInt(this.#s);
+        return (s <= BN_N_2);
+    }
+
+    /**
+     *  The ``v`` value for a signature.
+     *
+     *  Since a given ``x`` value for ``r`` has two possible values for
+     *  its correspondin ``y``, the ``v`` indicates which of the two ``y``
+     *  values to use.
+     *
+     *  It is normalized to the values ``27`` or ``28`` for legacy
+     *  purposes.
+     */
+    get v(): 27 | 28 { return this.#v; }
+    set v(value: BigNumberish) {
+        const v = getNumber(value, "value");
+        assertArgument(v === 27 || v === 28, "invalid v", "v", value);
+        this.#v = v;
+    }
+
+    /**
+     *  The EIP-155 ``v`` for legacy transactions. For non-legacy
+     *  transactions, this value is ``null``.
+     */
+    get networkV(): null | bigint { return this.#networkV; }
+
+    /**
+     *  The chain ID for EIP-155 legacy transactions. For non-legacy
+     *  transactions, this value is ``null``.
+     */
+    get legacyChainId(): null | bigint {
+        const v = this.networkV;
+        if (v == null) { return null; }
+        return Signature.getChainId(v);
+    }
+
+    /**
+     *  The ``yParity`` for the signature.
+     *
+     *  See ``v`` for more details on how this value is used.
+     */
+    get yParity(): 0 | 1 {
+        return (this.v === 27) ? 0: 1;
+    }
+
+    /**
+     *  The [[link-eip-2098]] compact representation of the ``yParity``
+     *  and ``s`` compacted into a single ``bytes32``.
+     */
+    get yParityAndS(): string {
+        // The EIP-2098 compact representation
+        const yParityAndS = getBytes(this.s);
+        if (this.yParity) { yParityAndS[0] |= 0x80; }
+        return hexlify(yParityAndS);
+    }
+
+    /**
+     *  The [[link-eip-2098]] compact representation.
+     */
+    get compactSerialized(): string {
+        return concat([ this.r, this.yParityAndS ]);
+    }
+
+    /**
+     *  The serialized representation.
+     */
+    get serialized(): string {
+        return concat([ this.r, this.s, (this.yParity ? "0x1c": "0x1b") ]);
+    }
+
+    /**
+     *  @private
+     */
+    constructor(guard: any, r: string, s: string, v: 27 | 28) {
+        assertPrivate(guard, _guard, "Signature");
+        this.#r = r;
+        this.#s = s;
+        this.#v = v;
+        this.#networkV = null;
+    }
+
+    /**
+     *  Returns the canonical signature.
+     *
+     *  This is only necessary when dealing with legacy transaction which
+     *  did not enforce canonical S values (i.e. [[link-eip-2]]. Most
+     *  developers should never require this.
+     */
+    getCanonical(): Signature {
+        if (this.isValid()) { return this; }
+
+        // Compute the canonical signature; s' = N - s, v = !v
+        const s = BN_N - BigInt(this._s);
+        const v = <27 | 28>(55 - this.v);
+        const result = new Signature(_guard, this.r, toUint256(s), v);
+
+        // Populate the networkV if necessary
+        if (this.networkV) { result.#networkV =  this.networkV; }
+
+        return result;
+    }
+
+    /**
+     *  Returns a new identical [[Signature]].
+     */
+    clone(): Signature {
+        const clone = new Signature(_guard, this.r, this._s, this.v);
+        if (this.networkV) { clone.#networkV = this.networkV; }
+        return clone;
+    }
+
+    /**
+     *  Returns a representation that is compatible with ``JSON.stringify``.
+     */
+    toJSON(): any {
+        const networkV = this.networkV;
+        return {
+            _type: "signature",
+            networkV: ((networkV != null) ? networkV.toString(): null),
+            r: this.r, s: this._s, v: this.v,
+        };
+    }
+
+    [inspect](): string {
+        return this.toString();
+    }
+
+    toString(): string {
+        if (this.isValid()) {
+            return `Signature { r: ${ this.r }, s: ${ this._s }, v: ${ this.v } }`;
+        }
+        return `Signature { r: ${ this.r }, s: ${ this._s }, v: ${ this.v }, valid: false }`;
+    }
+
+    /**
+     *  Compute the chain ID from the ``v`` in a legacy EIP-155 transactions.
+     *
+     *  @example:
+     *    Signature.getChainId(45)
+     *    //_result:
+     *
+     *    Signature.getChainId(46)
+     *    //_result:
+     */
+    static getChainId(v: BigNumberish): bigint {
+        const bv = getBigInt(v, "v");
+
+        // The v is not an EIP-155 v, so it is the unspecified chain ID
+        if ((bv == BN_27) || (bv == BN_28)) { return BN_0; }
+
+        // Bad value for an EIP-155 v
+        assertArgument(bv >= BN_35, "invalid EIP-155 v", "v", v);
+
+        return (bv - BN_35) / BN_2;
+    }
+
+    /**
+     *  Compute the ``v`` for a chain ID for a legacy EIP-155 transactions.
+     *
+     *  Legacy transactions which use [[link-eip-155]] hijack the ``v``
+     *  property to include the chain ID.
+     *
+     *  @example:
+     *    Signature.getChainIdV(5, 27)
+     *    //_result:
+     *
+     *    Signature.getChainIdV(5, 28)
+     *    //_result:
+     *
+     */
+    static getChainIdV(chainId: BigNumberish, v: 27 | 28): bigint {
+        return (getBigInt(chainId) * BN_2) + BigInt(35 + v - 27);
+    }
+
+    /**
+     *  Compute the normalized legacy transaction ``v`` from a ``yParirty``,
+     *  a legacy transaction ``v`` or a legacy [[link-eip-155]] transaction.
+     *
+     *  @example:
+     *    // The values 0 and 1 imply v is actually yParity
+     *    Signature.getNormalizedV(0)
+     *    //_result:
+     *
+     *    // Legacy non-EIP-1559 transaction (i.e. 27 or 28)
+     *    Signature.getNormalizedV(27)
+     *    //_result:
+     *
+     *    // Legacy EIP-155 transaction (i.e. >= 35)
+     *    Signature.getNormalizedV(46)
+     *    //_result:
+     *
+     *    // Invalid values throw
+     *    Signature.getNormalizedV(5)
+     *    //_error:
+     */
+    static getNormalizedV(v: BigNumberish): 27 | 28 {
+        const bv = getBigInt(v);
+
+        if (bv === BN_0 || bv === BN_27) { return 27; }
+        if (bv === BN_1 || bv === BN_28) { return 28; }
+
+        assertArgument(bv >= BN_35, "invalid v", "v", v);
+
+        // Otherwise, EIP-155 v means odd is 27 and even is 28
+        return (bv & BN_1) ? 27: 28;
+    }
+
+    /**
+     *  Creates a new [[Signature]].
+     *
+     *  If no %%sig%% is provided, a new [[Signature]] is created
+     *  with default values.
+     *
+     *  If %%sig%% is a string, it is parsed.
+     */
+    static from(sig?: SignatureLike): Signature {
+        function assertError(check: unknown, message: string): asserts check {
+            assertArgument(check, message, "signature", sig);
+        };
+
+        if (sig == null) {
+            return new Signature(_guard, ZeroHash, ZeroHash, 27);
+        }
+
+        if (typeof(sig) === "string") {
+            const bytes = getBytes(sig, "signature");
+            if (bytes.length === 64) {
+                const r = hexlify(bytes.slice(0, 32));
+                const s = bytes.slice(32, 64);
+                const v = (s[0] & 0x80) ? 28: 27;
+                s[0] &= 0x7f;
+                return new Signature(_guard, r, hexlify(s), v);
+            }
+
+            if (bytes.length === 65) {
+                const r = hexlify(bytes.slice(0, 32));
+                const s = hexlify(bytes.slice(32, 64));
+                const v = Signature.getNormalizedV(bytes[64]);
+                return new Signature(_guard, r, s, v);
+            }
+
+            assertError(false, "invalid raw signature length");
+        }
+
+        if (sig instanceof Signature) { return sig.clone(); }
+
+        // Get r
+        const _r = sig.r;
+        assertError(_r != null, "missing r");
+        const r = toUint256(_r);
+
+        // Get s; by any means necessary (we check consistency below)
+        const s = (function(s?: string, yParityAndS?: string) {
+            if (s != null) { return toUint256(s); }
+
+            if (yParityAndS != null) {
+                assertError(isHexString(yParityAndS, 32), "invalid yParityAndS");
+                const bytes = getBytes(yParityAndS);
+                bytes[0] &= 0x7f;
+                return hexlify(bytes);
+            }
+
+            assertError(false, "missing s");
+        })(sig.s, sig.yParityAndS);
+
+        // Get v; by any means necessary (we check consistency below)
+        const { networkV, v } = (function(_v?: BigNumberish, yParityAndS?: string, yParity?: Numeric): { networkV?: bigint, v: 27 | 28 } {
+            if (_v != null) {
+                const v = getBigInt(_v);
+                return {
+                    networkV: ((v >= BN_35) ? v: undefined),
+                    v: Signature.getNormalizedV(v)
+                };
+            }
+
+            if (yParityAndS != null) {
+                assertError(isHexString(yParityAndS, 32), "invalid yParityAndS");
+                return { v: ((getBytes(yParityAndS)[0] & 0x80) ? 28: 27) };
+            }
+
+            if (yParity != null) {
+                switch (getNumber(yParity, "sig.yParity")) {
+                    case 0: return { v: 27 };
+                    case 1: return { v: 28 };
+                }
+                assertError(false, "invalid yParity");
+            }
+
+            assertError(false, "missing v");
+        })(sig.v, sig.yParityAndS, sig.yParity);
+
+        const result = new Signature(_guard, r, s, v);
+        if (networkV) { result.#networkV =  networkV; }
+
+        // If multiple of v, yParity, yParityAndS we given, check they match
+        assertError(sig.yParity == null || getNumber(sig.yParity, "sig.yParity") === result.yParity, "yParity mismatch");
+        assertError(sig.yParityAndS == null || sig.yParityAndS === result.yParityAndS, "yParityAndS mismatch");
+
+        return result;
+    }
+}