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/provider-ankr.ts

@@ -0,0 +1,159 @@
+/**
+ *  [[link-ankr]] provides a third-party service for connecting to
+ *  various blockchains over JSON-RPC.
+ *
+ *  **Supported Networks**
+ *
+ *  - Ethereum Mainnet (``mainnet``)
+ *  - Goerli Testnet (``goerli``)
+ *  - Sepolia Testnet (``sepolia``)
+ *  - Arbitrum (``arbitrum``)
+ *  - Base (``base``)
+ *  - Base Goerlia Testnet (``base-goerli``)
+ *  - Base Sepolia Testnet (``base-sepolia``)
+ *  - BNB (``bnb``)
+ *  - BNB Testnet (``bnbt``)
+ *  - Filecoin (``filecoin``)
+ *  - Filecoin Calibration Testnet (``filecoin-calibration``)
+ *  - Optimism (``optimism``)
+ *  - Optimism Goerli Testnet (``optimism-goerli``)
+ *  - Optimism Sepolia Testnet (``optimism-sepolia``)
+ *  - Polygon (``matic``)
+ *  - Polygon Mumbai Testnet (``matic-mumbai``)
+ *
+ *  @_subsection: api/providers/thirdparty:Ankr  [providers-ankr]
+ */
+import {
+    defineProperties, FetchRequest, assertArgument
+} from "../utils/index.js";
+
+import { AbstractProvider } from "./abstract-provider.js";
+import { showThrottleMessage } from "./community.js";
+import { Network } from "./network.js";
+import { JsonRpcProvider } from "./provider-jsonrpc.js";
+
+import type { CommunityResourcable } from "./community.js";
+import type { Networkish } from "./network.js";
+import type { JsonRpcError, JsonRpcPayload } from "./provider-jsonrpc.js";
+
+
+const defaultApiKey = "9f7d929b018cdffb338517efa06f58359e86ff1ffd350bc889738523659e7972";
+
+function getHost(name: string): string {
+    switch (name) {
+        case "mainnet":
+            return "rpc.ankr.com/eth";
+        case "goerli":
+            return "rpc.ankr.com/eth_goerli";
+        case "sepolia":
+            return "rpc.ankr.com/eth_sepolia";
+
+        case "arbitrum":
+            return "rpc.ankr.com/arbitrum";
+        case "base":
+            return "rpc.ankr.com/base";
+        case "base-goerli":
+            return "rpc.ankr.com/base_goerli";
+        case "base-sepolia":
+            return "rpc.ankr.com/base_sepolia";
+        case "bnb":
+            return "rpc.ankr.com/bsc";
+        case "bnbt":
+            return "rpc.ankr.com/bsc_testnet_chapel";
+        case "filecoin":
+            return "rpc.ankr.com/filecoin";
+        case "filecoin-calibration":
+            return "rpc.ankr.com/filecoin_testnet";
+        case "matic":
+            return "rpc.ankr.com/polygon";
+        case "matic-mumbai":
+            return "rpc.ankr.com/polygon_mumbai";
+        case "optimism":
+            return "rpc.ankr.com/optimism";
+        case "optimism-goerli":
+            return "rpc.ankr.com/optimism_testnet";
+        case "optimism-sepolia":
+            return "rpc.ankr.com/optimism_sepolia";
+    }
+
+    assertArgument(false, "unsupported network", "network", name);
+}
+
+
+/**
+ *  The **AnkrProvider** connects to the [[link-ankr]]
+ *  JSON-RPC end-points.
+ *
+ *  By default, a highly-throttled API key is used, which is
+ *  appropriate for quick prototypes and simple scripts. To
+ *  gain access to an increased rate-limit, it is highly
+ *  recommended to [sign up here](link-ankr-signup).
+ */
+export class AnkrProvider extends JsonRpcProvider implements CommunityResourcable {
+
+    /**
+     *  The API key for the Ankr connection.
+     */
+    readonly apiKey!: string;
+
+    /**
+     *  Create a new **AnkrProvider**.
+     *
+     *  By default connecting to ``mainnet`` with a highly throttled
+     *  API key.
+     */
+    constructor(_network?: Networkish, apiKey?: null | string) {
+        if (_network == null) { _network = "mainnet"; }
+        const network = Network.from(_network);
+        if (apiKey == null) { apiKey = defaultApiKey; }
+
+        // Ankr does not support filterId, so we force polling
+        const options = { polling: true, staticNetwork: network };
+
+        const request = AnkrProvider.getRequest(network, apiKey);
+        super(request, network, options);
+
+        defineProperties<AnkrProvider>(this, { apiKey });
+    }
+
+    _getProvider(chainId: number): AbstractProvider {
+        try {
+            return new AnkrProvider(chainId, this.apiKey);
+        } catch (error) { }
+        return super._getProvider(chainId);
+    }
+
+    /**
+     *  Returns a prepared request for connecting to %%network%% with
+     *  %%apiKey%%.
+     */
+    static getRequest(network: Network, apiKey?: null | string): FetchRequest {
+        if (apiKey == null) { apiKey = defaultApiKey; }
+
+        const request = new FetchRequest(`https:/\/${ getHost(network.name) }/${ apiKey }`);
+        request.allowGzip = true;
+
+        if (apiKey === defaultApiKey) {
+            request.retryFunc = async (request, response, attempt) => {
+                showThrottleMessage("AnkrProvider");
+                return true;
+            };
+        }
+
+        return request;
+    }
+
+    getRpcError(payload: JsonRpcPayload, error: JsonRpcError): Error {
+        if (payload.method === "eth_sendRawTransaction") {
+            if (error && error.error && error.error.message === "INTERNAL_ERROR: could not replace existing tx") {
+                error.error.message = "replacement transaction underpriced";
+            }
+        }
+
+        return super.getRpcError(payload, error);
+    }
+
+    isCommunityResource(): boolean {
+        return (this.apiKey === defaultApiKey);
+    }
+}