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/.github/workflows/android.yml b/.github/workflows/android.yml
index 6dd744d..2c28410 100644
--- a/.github/workflows/android.yml
+++ b/.github/workflows/android.yml
@@ -2,9 +2,9 @@ name: Android CI/CD
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   build:
@@ -36,7 +36,7 @@ jobs:
           android-app/app/build/outputs/apk/androidTest/debug/app-debug-androidTest.apk
 
     - name: upload artifact to Firebase App Distribution
-      if: github.ref == 'refs/heads/master'
+      if: github.ref == 'refs/heads/main'
       uses: wzieba/Firebase-Distribution-Github-Action@v1
       with:
         appId: ${{secrets.FIREBASE_APP_ID}}