fix: restore dark mode, fix depth tile source, show FADs by default

- Remove MODE_NIGHT_NO from NavApplication — system dark mode now respected;
  NightVision toggle (red-on-black) is separate and unaffected
- Depth layer: swap empty OpenSeaMap depth tiles for NOAA CoastWatch ETOPO180
  WMS which has full Pacific/Hawaii coverage
- FADs default to visible (was off) since Hawaii DAR data is loaded at startup

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 6 insertions, 5 deletions

diff --git a/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt b/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt
index 8e6bdfa..3873002 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt
@@ -1,7 +1,6 @@
 package org.terst.nav
 
 import android.app.Application
-import androidx.appcompat.app.AppCompatDelegate
 import com.google.firebase.crashlytics.FirebaseCrashlytics
 import org.terst.nav.db.NavDatabase
 import org.terst.nav.settings.FeatureFlags
@@ -39,7 +38,6 @@ class NavApplication : Application() {
 
     override fun onCreate() {
         super.onCreate()
-        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
         featureFlags = FeatureFlags(this)
         database = NavDatabase.get(this)
         logbookRepository = org.terst.nav.logbook.LogbookRepository(org.terst.nav.logbook.LogbookStorage(this))
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt
index 9f7e819..73f6684 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt
@@ -36,7 +36,7 @@ class MapLayerManager(context: Context) {
         private set
     var depthEnabled: Boolean    = prefs.getBoolean(KEY_DEPTH,        false)
         private set
-    var fadsEnabled: Boolean     = prefs.getBoolean(KEY_FADS,         false)
+    var fadsEnabled: Boolean     = prefs.getBoolean(KEY_FADS,         true)
         private set
     var sstEnabled: Boolean      = prefs.getBoolean(KEY_SST,          false)
         private set
@@ -76,9 +76,12 @@ class MapLayerManager(context: Context) {
             "https://tile.openweathermap.org/map/wind_new/{z}/{x}/{y}.png?appid=ae2a038149aa0900d1bc74160aa2a37e"
         private const val URL_SEAMARKS =
             "https://tiles.openseamap.org/seamark/{z}/{x}/{y}.png"
-        // Depth soundings + contours from OpenSeaMap (zoom 3–18, coverage varies by region)
+        // GEBCO 2023 global bathymetry — full Pacific coverage via NOAA CoastWatch WMS
         private const val URL_DEPTH =
-            "https://tiles.openseamap.org/depth/{z}/{x}/{y}.png"
+            "https://coastwatch.pfeg.noaa.gov/erddap/wms/etopo180/request" +
+            "?SERVICE=WMS&REQUEST=GetMap&VERSION=1.3.0&LAYERS=etopo180:altitude" +
+            "&CRS=EPSG:3857&BBOX={bbox-epsg-3857}&FORMAT=image/png&TRANSPARENT=TRUE" +
+            "&WIDTH=256&HEIGHT=256&STYLES="
         // Sea Surface Temperature from NOAA CoastWatch (WMS-style raster)
         private const val URL_SST =
             "https://coastwatch.pfeg.noaa.gov/erddap/wms/jplMURSST41/request" +