Refactor: Move data-access code to Typescript w/ shared interface

app/sql_channel.js

@@ -1,6 +1,6 @@
 const electron = require('electron');
 const Queue = require('p-queue').default;
-const sql = require('./sql');
+const sql = require('../ts/sql/Server').default;
 const { remove: removeUserConfig } = require('./user_config');
 const { remove: removeEphemeralConfig } = require('./ephemeral_config');
 

app/user_config.d.ts

@@ -0,0 +1 @@
+export function remove(): void;