Revert "run optimizer.ts (coordinator) on main thread"

This reverts commit 146d220.

src/state/async/calculationThunks.ts

@@ -2,7 +2,6 @@
 /* eslint-disable no-await-in-loop */
 /* eslint-disable no-console */
 import { freeze } from '@reduxjs/toolkit';
-import { next, setup } from '../optimizer/optimizer';
 import type { Character } from '../optimizer/optimizerCore';
 import { ERROR, RUNNING, STOPPED, SUCCESS, WAITING } from '../optimizer/status';
 import type { AppThunk } from '../redux-hooks';
@@ -22,6 +21,10 @@ import { getParsedJsHeuristicsTarget } from '../slices/extras';
 
 let resume: (() => void) | undefined;
 
+const worker = new ComlinkWorker<typeof import('../optimizer/optimizer')>(
+  new URL('../optimizer/optimizer.ts', import.meta.url),
+);
+
 export const startCalc: AppThunk = async (dispatch, getState) => {
   const reduxState = getState();
 
@@ -51,11 +54,13 @@ export const startCalc: AppThunk = async (dispatch, getState) => {
     let elapsed = 0;
     let timer = performance.now();
 
-    await setup(reduxState, jsHeuristicsEnabled, jsHeuristicsTarget, threads);
+    await worker.setup(reduxState, jsHeuristicsEnabled, jsHeuristicsTarget, threads);
+
+    let nextPromise = worker.next();
 
     // eslint-disable-next-line no-constant-condition
     while (true) {
-      const result = await next();
+      const result = await nextPromise;
 
       const { percent, heuristicsPercent, isChanged, list, filteredLists } = result.value;
       currentPercent = percent;
@@ -81,6 +86,9 @@ export const startCalc: AppThunk = async (dispatch, getState) => {
         break;
       }
 
+      // concurrency: send next request to worker thread before rendering current on main thread
+      nextPromise = worker.next();
+
       dispatch(
         updateResults({
           list: currentList,