Implement mobile-first navigation with tabs, server-side auto-connect, improve mobile UX (#1008)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: thomasnordquist <7721625+thomasnordquist@users.noreply.github.com>
Co-authored-by: Thomas Nordquist <thomasnordquist@users.noreply.github.com>

.gitignore

@@ -27,12 +27,44 @@ app/.webpack-cache
 
 # Demo video artifacts
 scenes.json
+scenes-mobile.json
 segment-*.mp4
 segment-*.gif
 ui-test.mp4
 ui-test.gif
+ui-test-mobile.mp4
+ui-test-mobile.gif
 app.mp4
 app2.mp4
+app-mobile.mp4
+app2-mobile.mp4
 app720.gif
 qrawvideorgb24.yuv
-intro.png
+qrawvideorgb24-mobile.yuv
+intro.png
+intro-mobile.png
+palette.png
+palette-mobile.png
+ffmpeg_info
+ffmpeg_info_mobile# Mobile test artifacts
+qrawvideorgb24-mobile.yuv
+*.yuv
+segment-mobile-*.gif
+mobile-demo.mp4
+mobile-demo.gif
+final-mobile-tree.png
+mobile-tree-debug.png
+mobile-render-debug.png
+tree-state-check.png
+server*.log
+
+# Test scripts
+test-mobile-tree.js
+check-*.js
+debug-*.js
+inspect-*.js
+final-*.js
+publish-test*.js
+verify-mobile-tree.js
+interactive-mobile-test.js
+long-wait-test.js