Integrate webapp (simulator) into docs workflow

- Merge deploy-webapp.yml into docs.yml workflow
- Build simulator and place at /simulator/ subdirectory
- Update docs links to use relative paths to simulator
- Remove separate deploy-webapp.yml to avoid conflicts

The combined workflow now:
1. Builds docs with zensical
2. Builds webapp with shinylive
3. Copies webapp to site/simulator/
4. Deploys everything to GitHub Pages

Simulator will be at adaptive-lighting.nijho.lt/simulator/

docs/advanced/brightness-modes.md

@@ -118,7 +118,7 @@ These graphs were generated using the values calculated by the Adaptive Lighting
 The best way to understand brightness modes is to experiment with the interactive simulator:
 
 <div style="text-align: center; margin: 2rem 0;">
-  <a href="https://basnijholt.github.io/adaptive-lighting" class="simulator-link">
+  <a href="../simulator/" class="simulator-link">
     🌞 Try the Simulator 🌛
   </a>
 </div>

docs/index.md

@@ -18,7 +18,7 @@ hide:
   <a href="https://my.home-assistant.io/redirect/hacs_repository/?owner=basnijholt&repository=adaptive-lighting&category=integration" class="md-button md-button--primary">
     Install via HACS
   </a>
-  <a href="https://basnijholt.github.io/adaptive-lighting" class="md-button">
+  <a href="simulator/" class="md-button">
     Try the Simulator
   </a>
 </div>
@@ -82,7 +82,7 @@ Adaptive Lighting provides four switches for each configuration (using "living_r
 Visualize how Adaptive Lighting will work with your settings using the interactive simulator:
 
 <div style="text-align: center; margin: 2rem 0;">
-  <a href="https://basnijholt.github.io/adaptive-lighting" class="simulator-link">
+  <a href="simulator/" class="simulator-link">
     🌞 Adaptive Lighting Simulator 🌛
   </a>
 </div>

docs/see-also.md

@@ -28,7 +28,7 @@ Resources, tutorials, and related projects for Adaptive Lighting.
 Visualize how different settings affect your lighting throughout the day:
 
 <div style="text-align: center; margin: 2rem 0;">
-  <a href="https://basnijholt.github.io/adaptive-lighting" class="simulator-link">
+  <a href="../simulator/" class="simulator-link">
     🌞 Open the Simulator 🌛
   </a>
 </div>