Add ads system, diversify callers, update website descriptions

- Add ads playback system with backend endpoints and frontend UI
- Diversify AI callers: randomize voices per session, expand jobs/problems/interests/quirks/locations
- Update website tagline and descriptions to "biologically questionable organisms"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/index.html

@@ -81,6 +81,16 @@
                 </div>
             </section>
 
+            <!-- Ads -->
+            <section class="music-section">
+                <h2>Ads</h2>
+                <select id="ad-select"></select>
+                <div class="music-controls">
+                    <button id="ad-play-btn">Play Ad</button>
+                    <button id="ad-stop-btn">Stop</button>
+                </div>
+            </section>
+
             <!-- Sound Effects -->
             <section class="sounds-section">
                 <h2>Sounds</h2>