separate account from other data for backup/restore

src/db/tables/accounts.ts

@@ -0,0 +1,15 @@
+export type Account = {
+  id?: number; // auto-generated by Dexie
+  dateCreated: string;
+  derivationPath: string;
+  identity: string;
+  publicKeyHex: string;
+  mnemonic: string;
+};
+
+// mark encrypted field by starting with a $ character
+// see https://github.com/PVermeer/dexie-addon-suite-monorepo/tree/master/packages/dexie-encrypted-addon
+export const AccountsSchema = {
+  accounts:
+    "++id, dateCreated, derivationPath, $identity, $mnemonic, publicKeyHex",
+};