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/phase-f-llm.test.ts

@@ -1,5 +1,6 @@
 import { browser, expect } from '@wdio/globals';
 import { isJudgeAvailable, assertWithJudge } from '../infra/llm-judge';
+import { exec } from '../helpers/execute.ts';
 
 // Phase F — LLM-Judged Tests (F4–F7)
 // Settings completeness, theme system quality, error handling, and UI consistency.
@@ -11,7 +12,7 @@ async function openSettings(): Promise<void> {
   const panel = await browser.$('.settings-panel');
   const isOpen = await panel.isDisplayed().catch(() => false);
   if (!isOpen) {
-    await browser.execute(() => {
+    await exec(() => {
       const btn = document.querySelector('[data-testid="settings-btn"]');
       if (btn) (btn as HTMLElement).click();
     });
@@ -31,7 +32,7 @@ async function openSettings(): Promise<void> {
 async function closeSettings(): Promise<void> {
   const panel = await browser.$('.settings-panel');
   if (await panel.isDisplayed().catch(() => false)) {
-    await browser.execute(() => {
+    await exec(() => {
       const btn = document.querySelector('.settings-close, .panel-close');
       if (btn) (btn as HTMLElement).click();
     });
@@ -41,7 +42,7 @@ async function closeSettings(): Promise<void> {
 
 /** Click a settings category by label text. */
 async function clickSettingsCategory(label: string): Promise<boolean> {
-  return browser.execute((lbl) => {
+  return exec((lbl) => {
     const items = document.querySelectorAll('.settings-sidebar button, .settings-sidebar [role="tab"]');
     for (const item of items) {
       if (item.textContent?.includes(lbl)) {
@@ -55,7 +56,7 @@ async function clickSettingsCategory(label: string): Promise<boolean> {
 
 /** Get visible text content of settings content area. */
 async function getSettingsContent(): Promise<string> {
-  return browser.execute(() => {
+  return exec(() => {
     const content = document.querySelector('.settings-content, .settings-panel');
     return content?.textContent ?? '';
   });
@@ -129,13 +130,13 @@ describe('Scenario F5 — LLM-Judged Theme System Quality', () => {
     await browser.pause(300);
 
     // Open theme dropdown to capture options
-    await browser.execute(() => {
+    await exec(() => {
       const trigger = document.querySelector('.custom-dropdown .dropdown-trigger');
       if (trigger) (trigger as HTMLElement).click();
     });
     await browser.pause(300);
 
-    const themeHtml = await browser.execute(() => {
+    const themeHtml = await exec(() => {
       const panel = document.querySelector('.settings-content, .settings-panel');
       if (!panel) return '';
       // Get appearance section HTML for structure analysis
@@ -143,7 +144,7 @@ describe('Scenario F5 — LLM-Judged Theme System Quality', () => {
     });
 
     // Close dropdown
-    await browser.execute(() => document.body.click());
+    await exec(() => document.body.click());
     await browser.pause(200);
 
     const verdict = await assertWithJudge(
@@ -170,7 +171,7 @@ describe('Scenario F6 — LLM-Judged Error Handling Quality', () => {
     }
 
     // Capture any visible toast notifications, error states, or warnings
-    const errorContent = await browser.execute(() => {
+    const errorContent = await exec(() => {
       const results: string[] = [];
 
       // Check toast notifications
@@ -216,7 +217,7 @@ describe('Scenario F7 — LLM-Judged Overall UI Quality', () => {
     }
 
     // Capture full page structure and key visual elements
-    const uiSnapshot = await browser.execute(() => {
+    const uiSnapshot = await exec(() => {
       const elements: string[] = [];
 
       // Sidebar rail