[3.0] Theme split (wave 1, part 3) — Drop the unused jQuery Custom Scrollbar

[albertlast]

Wave 1, part 3 of breaking up #7933. No theme templates touched.

Theme::loadJavaScript() loads jquery.custom-scrollbar.js and its stylesheet on every page for every logged-in member:

if (!User::$me->is_guest) {
	self::loadJavaScriptFile('jquery.custom-scrollbar.js', ['minimize' => true], 'smf_jquery_scrollbar');
	self::loadCSSFile('jquery.custom-scrollbar.css', ['force_current' => false, 'validate' => true], 'smf_scrollbar');
}

Nothing calls customScrollbar(). Grepping Sources/ and Themes/default/ for customScrollbar, custom-scrollbar, smf_jquery_scrollbar and smf_scrollbar finds only the plugin itself and these two lines. So it is 942 lines of JS and CSS downloaded and parsed for nothing.

Removes both files, both loader calls, and the credit entry, since the library is no longer bundled. #7933 leaves the credit behind; that looks like an oversight rather than a decision.

Not included: #7933 also adds defer to smf_jquery_plugins.js and theme.js in the same block. That is a separate change with its own risks, so it is left for the part that deals with script loading.

Testing

• Board index, a topic, profile, personal messages, credits and the admin centre all load with no scrollbar references in the markup, and no console errors.
• jQuery.fn.customScrollbar is undefined — confirming nothing was relying on it.

🤖 Generated with Claude Code

[live627]

this related CSS rule can go

SMF/Themes/default/css/index.css

Lines 926 to 928 in fcbc3cb

	.top_menu.scrollable {
	max-height: 30em;
	}