release: v2.12.0 - ISS SSTV decoder, update notifications, UI improvements

- Add ISS SSTV decoder mode with real-time tracking globe
- Add GitHub update notifications for new releases
- Enhance Meshtastic with QR codes and telemetry display
- Add new Space category for satellite modes
- Fix SoapySDR detection, dump1090 builds, and Flask compatibility
- Update version numbers and changelog

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/index.html

@@ -35,7 +35,7 @@
             </div>
             <div class="hero-stats">
                 <div class="stat">
-                    <span class="stat-value">12+</span>
+                    <span class="stat-value">15+</span>
                     <span class="stat-label">Modes</span>
                 </div>
                 <div class="stat">
@@ -142,6 +142,12 @@
                     <h3>Meshtastic</h3>
                     <p>LoRa mesh network integration. Connect to Meshtastic devices for decentralized, long-range communication monitoring.</p>
                 </div>
+
+                <div class="feature-card">
+                    <div class="feature-icon">🖼️</div>
+                    <h3>ISS SSTV</h3>
+                    <p>Receive Slow Scan Television from the ISS. Real-time tracking globe, pass predictions, and image decoding.</p>
+                </div>
             </div>
         </div>
     </section>