merge: reconcile master particle-wind work with origin/main redesign

Merged divergent branches (common ancestor a9d87b6). Took origin/main
as base (layer manager, recenter, quit button, GPX tracks, marine
conditions, dark theme, user position layer, active/past track layers)
and layered in particle wind simulation work:

- MapHandler: added setupWindLayer, updateWindLayer, updateWindGridLayer;
  kept their user-pos layer, follow/recenter state, active+past tracks
- WeatherRepository: kept their fetchCurrentConditions, added fetchWindGrid
- MainViewModel: kept their track/marine/summary changes, added windGrid
  StateFlow, loadWindGrid, buildGrid
- MainActivity: kept their full UI (layer picker, quit, recenter, fade
  animations), added particleWindView wiring, weatherLoaded guard,
  windArrow/windGrid observers
- activity_main.xml: took their LinearLayout redesign, added ParticleWindView
  overlay inside ConstraintLayout

https://claude.ai/code/session_01HXPjBsogsJVRwCiekDGkJX

1 files changed, 3 insertions, 3 deletions

diff --git a/android-app/app/src/main/res/menu/bottom_nav_menu.xml b/android-app/app/src/main/res/menu/bottom_nav_menu.xml
index b29fb08..e7fc15d 100644
--- a/android-app/app/src/main/res/menu/bottom_nav_menu.xml
+++ b/android-app/app/src/main/res/menu/bottom_nav_menu.xml
@@ -5,9 +5,9 @@
         android:icon="@drawable/ic_map"
         android:title="Map" />
     <item
-        android:id="@+id/nav_instruments"
-        android:icon="@drawable/ic_instruments"
-        android:title="Instruments" />
+        android:id="@+id/nav_layers"
+        android:icon="@drawable/ic_layers"
+        android:title="Layers" />
     <item
         android:id="@+id/nav_log"
         android:icon="@drawable/ic_log"