refactor: extract frustration tracking into separate add-on script

Move rage click and dead click detection (35% of script.js) into
script.frustration.js as an optional add-on. Core script drops from
8.1KB to 5.7KB gzipped. Add-on auto-discovers core via window.pulse
polling and supports opt-out via data-no-rage/data-no-dead attributes.

- Expose cleanPath on window.pulse for add-on consumption
- Add script.frustration.js to middleware PUBLIC_ROUTES
- Update integration guides, ScriptSetupBlock, and FrustrationTable
  empty state to reference the add-on script

components/IntegrationGuide.tsx

@@ -67,6 +67,18 @@ export function IntegrationGuide({ integration, children }: IntegrationGuideProp
 
         <div className="prose prose-neutral dark:prose-invert max-w-none">
           {children}
+
+          <hr className="my-8 border-neutral-200 dark:border-neutral-800" />
+          <h3>Optional: Frustration Tracking</h3>
+          <p>
+            Detect rage clicks and dead clicks by adding the frustration tracking
+            add-on after the core script:
+          </p>
+          <pre><code>{`<script defer src="https://pulse.ciphera.net/script.frustration.js"></script>`}</code></pre>
+          <p>
+            No extra configuration needed. Add <code>data-no-rage</code> or{' '}
+            <code>data-no-dead</code> to disable individual signals.
+          </p>
         </div>
 
         {/* * --- Related Integrations --- */}