Point the design notes at the project page instead of the deploy URL

The guide linked straight to the Render hostname in three places. That URL is
an artifact of where it happens to be hosted; the project page is the stable
entry point and already carries the demo link.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PoBAfwRzHozF2bhZumxjPk

docs/GUIDE.md

@@ -911,4 +911,4 @@ The largest ones:
 ---
 
 *Source: [github.com/parththakkar106/AI-DnD](https://github.com/parththakkar106/AI-DnD) ·
-Live demo: [ai-dnd-1gmp.onrender.com](https://ai-dnd-1gmp.onrender.com)*
+[Project page](https://parththakkar106.github.io/AI-DnD/)*

docs/guide.html

@@ -313,7 +313,7 @@ footer a { color: var(--gold); }
   <p class="meta">
     Written to be read end to end. Every section states the decision, the reasoning behind
     it, and what it cost. ·
-    <a href="https://ai-dnd-1gmp.onrender.com">Live demo</a> ·
+    <a href="https://parththakkar106.github.io/AI-DnD/">Project page</a> ·
     <a href="https://github.com/parththakkar106/AI-DnD">Source</a>
   </p>
 </header>
@@ -1309,7 +1309,6 @@ largest ones:</p>
   <div class="wrap">
     <p><strong>AI D&amp;D</strong> — design notes ·
     <a href="https://github.com/parththakkar106/AI-DnD">Source on GitHub</a> ·
-    <a href="https://ai-dnd-1gmp.onrender.com">Live demo</a> ·
     <a href="https://parththakkar106.github.io/AI-DnD/">Project page</a></p>
     <p>Full source for every claim here is in the repo; the file paths are named inline.</p>
   </div>