fix(e2e): cross-protocol browser.execute() — works with both WebDriver + CDP

Root cause: WebDriverIO devtools protocol wraps functions in a polyfill
that puts `return` inside eval() (not a function body) → "Illegal return".

Fix: exec() wrapper in helpers/execute.ts converts function args to IIFE
strings before passing to browser.execute(). Works identically on both
WebDriver (Tauri) and CDP/devtools (Electrobun CEF).

- 35 spec files updated (browser.execute → exec)
- 4 config files updated (string-form expressions)
- helpers/actions.ts + assertions.ts updated
- 560 vitest + 116 cargo passing

tests/e2e/specs/theme.test.ts

@@ -6,6 +6,7 @@ import { browser, expect } from '@wdio/globals';
 import * as S from '../helpers/selectors.ts';
 import { openSettings, closeSettings, switchSettingsCategory } from '../helpers/actions.ts';
 import { assertThemeApplied } from '../helpers/assertions.ts';
+import { exec } from '../helpers/execute.ts';
 
 describe('Theme system', () => {
   before(async () => {
@@ -19,7 +20,7 @@ describe('Theme system', () => {
   });
 
   it('should show theme dropdown button', async () => {
-    const exists = await browser.execute(() => {
+    const exists = await exec(() => {
       return (document.querySelector('.dd-btn')
         ?? document.querySelector('.dropdown-btn')
         ?? document.querySelector('.custom-dropdown')) !== null;
@@ -28,14 +29,14 @@ describe('Theme system', () => {
   });
 
   it('should open theme dropdown on click', async () => {
-    await browser.execute(() => {
+    await exec(() => {
       const btn = document.querySelector('.dd-btn')
         ?? document.querySelector('.dropdown-btn');
       if (btn) (btn as HTMLElement).click();
     });
     await browser.pause(300);
 
-    const listOpen = await browser.execute(() => {
+    const listOpen = await exec(() => {
       const list = document.querySelector('.dd-list')
         ?? document.querySelector('.dropdown-menu');
       if (!list) return false;
@@ -47,7 +48,7 @@ describe('Theme system', () => {
   });
 
   it('should show theme groups (Catppuccin, Editor, Deep Dark)', async () => {
-    const texts = await browser.execute(() => {
+    const texts = await exec(() => {
       const labels = document.querySelectorAll('.dd-group-label, .dropdown-group-label');
       return Array.from(labels).map(l => l.textContent ?? '');
     });
@@ -60,7 +61,7 @@ describe('Theme system', () => {
   });
 
   it('should list at least 17 theme options', async () => {
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       return (document.querySelectorAll('.dd-item').length
         || document.querySelectorAll('.dropdown-item').length);
     });
@@ -70,7 +71,7 @@ describe('Theme system', () => {
   });
 
   it('should highlight the currently selected theme', async () => {
-    const hasSelected = await browser.execute(() => {
+    const hasSelected = await exec(() => {
       return (document.querySelector('.dd-item.selected')
         ?? document.querySelector('.dropdown-item.active')) !== null;
     });
@@ -84,7 +85,7 @@ describe('Theme system', () => {
   });
 
   it('should have 4 Catppuccin themes', async () => {
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       const items = document.querySelectorAll('.dd-item, .dropdown-item');
       let catCount = 0;
       const catNames = ['mocha', 'macchiato', 'frapp', 'latte'];
@@ -100,7 +101,7 @@ describe('Theme system', () => {
   });
 
   it('should have 7 Editor themes', async () => {
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       const items = document.querySelectorAll('.dd-item, .dropdown-item');
       const editorNames = ['vscode', 'atom', 'monokai', 'dracula', 'nord', 'solarized', 'github'];
       let edCount = 0;
@@ -116,7 +117,7 @@ describe('Theme system', () => {
   });
 
   it('should have 6 Deep Dark themes', async () => {
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       const items = document.querySelectorAll('.dd-item, .dropdown-item');
       const deepNames = ['tokyo', 'gruvbox', 'ayu', 'poimandres', 'vesper', 'midnight'];
       let deepCount = 0;
@@ -136,7 +137,7 @@ describe('Theme system', () => {
     await browser.keys('Escape');
     await browser.pause(200);
 
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       return (document.querySelectorAll('.size-stepper').length
         || document.querySelectorAll('.font-stepper').length
         || document.querySelectorAll('.stepper').length);
@@ -147,7 +148,7 @@ describe('Theme system', () => {
   });
 
   it('should show theme action buttons', async () => {
-    const count = await browser.execute(() => {
+    const count = await exec(() => {
       return document.querySelectorAll('.theme-action-btn').length;
     });
     if (count > 0) {
@@ -156,7 +157,7 @@ describe('Theme system', () => {
   });
 
   it('should apply font changes to terminal', async () => {
-    const fontFamily = await browser.execute(() => {
+    const fontFamily = await exec(() => {
       return getComputedStyle(document.documentElement).getPropertyValue('--term-font-family').trim();
     });
     expect(typeof fontFamily).toBe('string');