Optimize shortcode detection before rendering

[CySSoO]

Motivation

• The shortcode pipeline was being invoked for pages that contained [ characters in HTML/JS, causing unnecessary CPU time in hookActionOutputHTMLBefore.
• The goal is to skip the heavy shortcode renderer when no real shortcode or Smarty/hook token is present.

Description

• Tighten EverblockTools::hasShortcodeToken() by returning early for empty content and when the string contains neither [ nor { to avoid needless work.
• Remove the broad [ needle and instead keep Smarty/hook tokens ({hook h=, {$, {if, {foreach, {include}) detection while adding a regex check for shortcode shapes like [tag] or [tag ...].
• Change is implemented in src/Service/EverblockTools.php and preserves detection for Smarty/hook markers while reducing false positives from plain HTML/JS.

Testing

• Ran PHP lint on the modified file with php -l src/Service/EverblockTools.php, which reported no syntax errors.

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Codex Task