Add unique URLs and share component

Create unique URLs for interactives and add the SocialShare component to the bottom of the Rules of Inference Playground.

src/pages/RulesOfInferencePlaygroundPage.tsx

@@ -41,7 +41,7 @@ const RulesOfInferencePlaygroundPage = () => {
         <SocialShare 
           title="Rules of Inference Playground - Interactive Logic Learning"
           description="Practice applying resolution and equivalence rules to derive conclusions step by step in this interactive logic playground."
-          url={window.location.href}
+          url="https://lovable.dev/discrete-math/foundations/rules-of-inference"
         />
       </div>
     </div>