build(vite): resolve @/ alias in main + preload configs

The four renderer vite configs all resolve "@" to ./src; main and preload
didn't, so any main-reachable file using @/ imports would break the
bundle. Mirror the same alias block in both configs and revert
lib/errors.ts + src/main/* to the project's @/ convention.

js/src/lib/errors.ts

@@ -1,5 +1,5 @@
 import { z } from "zod";
-import { appEnv } from "../config/env";
+import { appEnv } from "@/config/env";
 
 export class ApiError extends Error {
   constructor(

js/src/main/ipc-utils.ts

@@ -1,5 +1,5 @@
 import { ipcMain, type IpcMainInvokeEvent } from "electron";
-import { reportError } from "../lib/errors";
+import { reportError } from "@/lib/errors";
 
 type InvokeHandler = (
   event: IpcMainInvokeEvent,

js/src/main/sentry.ts

@@ -1,7 +1,7 @@
 import { app } from "electron";
 import * as Sentry from "@sentry/electron/main";
-import { appConfig } from "../config/env";
-import { installErrorSinks } from "../lib/errors";
+import { appConfig } from "@/config/env";
+import { installErrorSinks } from "@/lib/errors";
 
 /**
  * Initialise Sentry for the main process. Captures uncaught exceptions from

js/vite.main.config.ts

@@ -1,7 +1,13 @@
+import path from "path";
 import { defineConfig } from 'vite';
 import { defineEnv } from './vite.env';
 
 // https://vitejs.dev/config
 export default defineConfig({
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
   define: defineEnv,
 });

js/vite.preload.config.ts

@@ -1,7 +1,13 @@
+import path from "path";
 import { defineConfig } from 'vite';
 import { defineEnv } from './vite.env';
 
 // https://vitejs.dev/config
 export default defineConfig({
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
   define: defineEnv,
 });