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/helpers/execute.ts

@@ -0,0 +1,52 @@
+/**
+ * Cross-protocol browser.execute() wrapper.
+ *
+ * WebDriverIO's devtools protocol (CDP via puppeteer-core) breaks when
+ * browser.execute() receives a function argument because:
+ *   1. WebDriverIO prepends a polyfill before `return (fn).apply(null, arguments)`
+ *   2. The devtools executeScript trims the script, finds no leading `return`,
+ *      and passes it directly to eval()
+ *   3. eval() fails with "Illegal return statement" because `return` is outside
+ *      a function body (the polyfill lines precede it)
+ *
+ * Fix: always pass a string expression to browser.execute(). Arguments are
+ * JSON-serialized and inlined into the script — no reliance on the `arguments`
+ * object which is protocol-dependent.
+ *
+ * Works identically with:
+ *   - WebDriver protocol (Tauri via tauri-driver)
+ *   - devtools/CDP protocol (Electrobun via CEF)
+ */
+
+import { browser } from '@wdio/globals';
+
+/**
+ * Execute a function in the browser, cross-protocol safe.
+ *
+ * Usage mirrors browser.execute():
+ *   exec(() => document.title)
+ *   exec((sel) => document.querySelector(sel) !== null, '.my-class')
+ *   exec((a, b) => a + b, 1, 2)
+ */
+export async function exec<R>(fn: (...args: any[]) => R, ...args: any[]): Promise<R> {
+  const fnStr = fn.toString();
+  const serializedArgs = args.map(a => JSON.stringify(a)).join(', ');
+  // Wrap as an IIFE expression — no `return` at the top level
+  const script = `return (${fnStr})(${serializedArgs})`;
+  return browser.execute(script) as Promise<R>;
+}
+
+/**
+ * Skip a test programmatically — works with both protocols.
+ *
+ * Mocha's this.skip() requires a non-arrow `function()` context. In
+ * WebDriverIO hooks (beforeTest), `this` may not carry the Mocha context
+ * with devtools protocol. This helper uses the same mechanism but is
+ * callable from any context that has the Mocha `this`.
+ *
+ * Usage inside `it('...', async function () { ... })`:
+ *   if (condition) { skipTest(this); return; }
+ */
+export function skipTest(ctx: Mocha.Context): void {
+  ctx.skip();
+}