fix: 🐛 Fix operator precedence in About customer URL href

[wapec]

The ternary and string concatenation were not grouped correctly — due to operator precedence, the expression evaluated as:
condition ? 'http://' : urlCustomer
instead of:
(condition ? 'http://' : '') + urlCustomer

When urlCustomer had no scheme, href became 'http://' with the actual URL silently dropped. Affects all white-labelled installations supplying customization.customer.www without a protocol prefix.

How to verify — logic level

Paste into any browser DevTools console:

const buggy = url => !/^https?:\/{2}/i.test(url) ? "http://" : '' + url;
const fixed = url => (!/^https?:\/{2}/i.test(url) ? 'http://' : '') + url;

console.table([
    'example.com',
    'www.example.com',
    'https://example.com',
    'http://example.com',
    'HTTPS://example.com',
].map(input => ({ input, buggy: buggy(input), fixed: fixed(input) })));

Expected output:

input	buggy	fixed
example.com	http://	http://example.com
example.com	http://	http://example.com
www.example.com	http://	http://www.example.com
https://example.com	https://example.com	https://example.com
http://example.com	http://example.com	http://example.com
HTTPS://example.com	HTTPS://example.com	HTTPS://example.com

Only inputs without an http:// / https:// scheme expose the bug. The
last three rows confirm the fix doesn't regress URLs that previously worked.

How to verify — UI

Open the mobile editor with customization.customer.www set in the editor
config. Navigate to Settings → About and inspect the customer URL link
(#settings-about-url):

<!-- buggy build, customer.www = "example.com" -->
<a id="settings-about-url" class="link external" href="http://" target="_blank">example.com</a>

<!-- fixed build, customer.www = "example.com" -->
<a id="settings-about-url" class="link external" href="http://example.com" target="_blank">example.com</a>

The visible link text is identical in both builds — only href differs,
which is why the bug is easy to miss in casual visual review.

Screenshots (Pixel 5, dark theme)

Input	Before (buggy)	After (fixed)
example.com
www.example.com

The red/green banner overlay at the top of each screenshot shows the actual
href attribute on the rendered link — that's where the divergence lives.

Test checklist

• customer.www = "example.com" → link href = http://example.com, click opens the site
• customer.www = "www.example.com" → link href = http://www.example.com, click opens the site
• customer.www = "http://example.com" → link href unchanged, click opens the site
• customer.www = "https://example.com" → link href unchanged, click opens the site
• customer.www = "HTTPS://example.com" → link href unchanged (case-insensitive)
• customer.www unset → link not rendered (existing urlCustomer?.length guard)