feat(ui): About in drawer; higher-contrast app icon & splash

Add an "About" entry to the navigation drawer (below Settings) so the
About screen is reachable without opening Settings first.

Recolour the launcher icon and native splash to a white sprout on brand
green (#2F7D34) — the previous dark-green-on-light-green had almost no
contrast. Regenerate Android, iOS and web icons and the light/dark splash.

apps/app_seeds/android/app/src/main/res/values-v31/styles.xml

@@ -6,7 +6,7 @@
         <item name="android:windowFullscreen">false</item>
         <item name="android:windowDrawsSystemBarBackgrounds">false</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
-        <item name="android:windowSplashScreenBackground">#E7F1E0</item>
+        <item name="android:windowSplashScreenBackground">#2F7D34</item>
         <item name="android:windowSplashScreenAnimatedIcon">@drawable/android12splash</item>
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.

apps/app_seeds/android/app/src/main/res/values/colors.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="ic_launcher_background">#E7F1E0</color>
+    <color name="ic_launcher_background">#2F7D34</color>
 </resources>