></dl>
<dl class="section version"><dt>Version</dt><dd>1.0 </dd></dl>
<dl class="section date"><dt>Date</dt><dd>2025-03-03</dd></dl>
<p>Debounced, ISR-driven button handling for three buttons:</p><ul>
<li>PLUS : selection up (0→1→…→7→0)</li>
<li>MINUS : selection down (7→6→…→0→7)</li>
<li>SET : short = toggle selected relay, long = clear error LED</li>
</ul>
<p>This header exposes only configuration macros, public state, types, and function prototypes. Implementation details live in <a c