Add currency settings, Settings service, and dialog to select fiat currency. Add support for non Official currencies like DOGE when using rates.

src/cli/autocomplete/complete.ts

@@ -23,7 +23,7 @@
  *   1 - Error (no output, fails silently for shell integration)
  */
 
-import { existsSync, readdirSync, readFileSync } from "node:fs";
+import { existsSync, readdirSync } from "node:fs";
 import { join } from "node:path";
 import { createHash } from "node:crypto";
 
@@ -34,6 +34,7 @@ import {
 } from "../../utils/paths.js";
 import { loadMnemonic } from "../mnemonic.js";
 import { Storage } from "../../services/storage.js";
+import { SettingsService } from "../../services/settings.js";
 import { COMMAND_TREE } from "./completions.js";
 
 // Lazy-loaded modules (only loaded when needed for dynamic completions)
@@ -103,12 +104,8 @@ function listSubcommands(command: string, prefix?: string): void {
  */
 function getCurrentMnemonic(): string | null {
   try {
-    const walletConfigPath = getWalletConfigPath();
-    if (!existsSync(walletConfigPath)) {
-      return null;
-    }
-
-    const mnemonicFile = readFileSync(walletConfigPath, "utf8").trim();
+    const settings = new SettingsService(getWalletConfigPath());
+    const mnemonicFile = settings.getDefaultMnemonic();
     if (!mnemonicFile) {
       return null;
     }