docs: add performance audit section and update benchmark link in documentation

Author: jayeshmepani

README.md

@@ -70,6 +70,14 @@ if ($result >= 0) {
 }
 ```
 
+## Performance Audit
+
+We have conducted a rigorous side-by-side benchmark comparing this FFI implementation against the native `php-sweph` C-extension.
+
+**[View the Interactive Performance Audit →](https://jayeshmepani.github.io/Swiss-Ephemeris-PHP/benchmark/benchmark.html)**
+
+The audit demonstrates **bit-perfect accuracy** and highly competitive performance across all 106 Swiss Ephemeris functions.
+
 ## Documentation
 
 **[Read the full documentation →](https://jayeshmepani.github.io/Swiss-Ephemeris-PHP/)**

docs/index.html

@@ -1369,7 +1369,7 @@ <h2>Performance</h2>
           <div class="info-box" style="border-left-color: var(--primary); background: rgba(37, 99, 235, 0.05);">
             <h3>🚀 Interactive Performance Audit</h3>
             <p>We conducted a rigorous 106-function side-by-side benchmark comparing this FFI implementation against the native <code>kevindecapite/php-sweph</code> C-extension.</p>
-            <a href="benchmark/benchmark.html" target="_blank" style="display: inline-block; margin-top: 1rem; padding: 0.75rem 1.5rem; background: var(--primary); color: white; border-radius: 0.5rem; text-decoration: none; font-weight: 700; transition: opacity 0.2s;">View Full FFI vs. C-Ext Report &rarr;</a>
+            <a href="benchmark/benchmark.html" target="_blank" style="display: inline-block; margin-top: 1rem; padding: 0.75rem 1.5rem; background: #2563eb; color: #ffffff !important; border-radius: 0.5rem; text-decoration: none; font-weight: 700; transition: opacity 0.2s; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);">View Full FFI vs. C-Ext Report &rarr;</a>
           </div>
           <div class="info-box">
             <h3>Tips for Optimal Performance</h3>