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/agent.test.ts

@@ -5,10 +5,11 @@
 import { browser, expect } from '@wdio/globals';
 import * as S from '../helpers/selectors.ts';
 import { sendPrompt } from '../helpers/actions.ts';
+import { exec } from '../helpers/execute.ts';
 
 describe('Agent pane', () => {
   it('should show the prompt input area', async () => {
-    const exists = await browser.execute((sel: string) => {
+    const exists = await exec((sel: string) => {
       return document.querySelector(sel) !== null;
     }, S.CHAT_INPUT);
     if (exists) {
@@ -39,7 +40,7 @@ describe('Agent pane', () => {
   });
 
   it('should show idle status by default', async () => {
-    const text = await browser.execute((sel: string) => {
+    const text = await exec((sel: string) => {
       const el = document.querySelector(sel);
       return el?.textContent?.toLowerCase() ?? '';
     }, S.AGENT_STATUS_TEXT);
@@ -50,7 +51,7 @@ describe('Agent pane', () => {
 
   it('should accept text in the prompt input', async () => {
     await sendPrompt('test prompt');
-    const value = await browser.execute(() => {
+    const value = await exec(() => {
       const ta = document.querySelector('.chat-input textarea') as HTMLTextAreaElement;
       if (ta) return ta.value;
       const inp = document.querySelector('.chat-input input') as HTMLInputElement;
@@ -62,7 +63,7 @@ describe('Agent pane', () => {
   });
 
   it('should show provider indicator', async () => {
-    const text = await browser.execute((sel: string) => {
+    const text = await exec((sel: string) => {
       const el = document.querySelector(sel);
       return el?.textContent ?? '';
     }, S.PROVIDER_BADGE);
@@ -72,7 +73,7 @@ describe('Agent pane', () => {
   });
 
   it('should show cost display', async () => {
-    const exists = await browser.execute((sel: string) => {
+    const exists = await exec((sel: string) => {
       return document.querySelector(sel) !== null;
     }, S.AGENT_COST);
     if (exists) {
@@ -82,7 +83,7 @@ describe('Agent pane', () => {
   });
 
   it('should show model selector or label', async () => {
-    const exists = await browser.execute((sel: string) => {
+    const exists = await exec((sel: string) => {
       return document.querySelector(sel) !== null;
     }, S.MODEL_LABEL);
     if (exists) {
@@ -93,7 +94,7 @@ describe('Agent pane', () => {
 
   it('should have tool call display structure', async () => {
     // Tool calls render inside details elements
-    const hasStructure = await browser.execute(() => {
+    const hasStructure = await exec(() => {
       return document.querySelector('.tool-call')
         ?? document.querySelector('.tool-group')
         ?? document.querySelector('details');
@@ -103,7 +104,7 @@ describe('Agent pane', () => {
   });
 
   it('should have timeline dots container', async () => {
-    const exists = await browser.execute(() => {
+    const exists = await exec(() => {
       return document.querySelector('.timeline')
         ?? document.querySelector('.turn-dots')
         ?? document.querySelector('.agent-timeline');
@@ -115,7 +116,7 @@ describe('Agent pane', () => {
     const stopBtn = await browser.$(S.STOP_BTN);
     if (await stopBtn.isExisting()) {
       // Stop button should not be displayed when agent is idle
-      const display = await browser.execute((sel: string) => {
+      const display = await exec((sel: string) => {
         const el = document.querySelector(sel);
         if (!el) return 'none';
         return getComputedStyle(el).display;
@@ -126,7 +127,7 @@ describe('Agent pane', () => {
   });
 
   it('should have context meter', async () => {
-    const exists = await browser.execute(() => {
+    const exists = await exec(() => {
       return document.querySelector('.context-meter')
         ?? document.querySelector('.usage-meter')
         ?? document.querySelector('.token-meter');
@@ -135,7 +136,7 @@ describe('Agent pane', () => {
   });
 
   it('should have prompt area with proper dimensions', async () => {
-    const dims = await browser.execute((sel: string) => {
+    const dims = await exec((sel: string) => {
       const el = document.querySelector(sel);
       if (!el) return null;
       const rect = el.getBoundingClientRect();
@@ -149,7 +150,7 @@ describe('Agent pane', () => {
 
   it('should clear prompt after send attempt', async () => {
     // Clear any existing text first
-    await browser.execute(() => {
+    await exec(() => {
       const ta = document.querySelector('.chat-input textarea') as HTMLTextAreaElement;
       if (ta) { ta.value = ''; ta.dispatchEvent(new Event('input')); }
     });