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, 9 insertions, 0 deletions

diff --git a/android-app/app/src/main/res/layout/fragment_safety.xml b/android-app/app/src/main/res/layout/fragment_safety.xml
index 5b2397e..f90420e 100644
--- a/android-app/app/src/main/res/layout/fragment_safety.xml
+++ b/android-app/app/src/main/res/layout/fragment_safety.xml
@@ -104,4 +104,13 @@
 
     </com.google.android.material.card.MaterialCardView>
 
+    <com.google.android.material.button.MaterialButton
+        android:id="@+id/button_plan_trip"
+        style="@style/Widget.Material3.Button.TonalButton"
+        android:layout_width="match_parent"
+        android:layout_height="60dp"
+        android:layout_marginTop="24dp"
+        android:text="PLAN TRIP (PRE-TRIP REPORT)"
+        app:layout_constraintTop_toBottomOf="@id/card_anchor" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>