parameterize main identifier (to prepare the way for multiple)

src/db/tables/accounts.ts

@@ -2,6 +2,7 @@ export type Account = {
   id?: number; // auto-generated by Dexie
   dateCreated: string;
   derivationPath: string;
+  did: string;
   identity: string;
   publicKeyHex: string;
   mnemonic: string;
@@ -11,5 +12,5 @@ export type Account = {
 // 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",
+    "++id, dateCreated, derivationPath, did, $identity, $mnemonic, publicKeyHex",
 };