Add Learn tab; move quit to Safety; remove persistent MOB FAB

UI cleanup:
- Remove always-visible MOB FAB — Safety screen button is sufficient
- Remove floating quit button; move to bottom of Safety screen
- fragment_container is now clickable/focusable, blocking map touch-through
  for all overlays (trip reports, log, safety)
- Record Track FAB hidden while any overlay is shown, visible on map tab

New Learn tab (5th nav item):
- Migration guides for Navionics and Sea People (local markdown via DocFragment)
- ASA Course Catalog, ASA Online Learning, ColRegs, Sailing Flashcards
  (open in browser)
- Remove blanket assets/ .gitignore so markdown docs are tracked

https://claude.ai/code/session_01HXPjBsogsJVRwCiekDGkJX

1 files changed, 2 insertions, 33 deletions

diff --git a/android-app/app/src/main/res/layout/activity_main.xml b/android-app/app/src/main/res/layout/activity_main.xml
index 5943949..1bb88b3 100644
--- a/android-app/app/src/main/res/layout/activity_main.xml
+++ b/android-app/app/src/main/res/layout/activity_main.xml
@@ -59,26 +59,10 @@
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:visibility="gone"
+                android:clickable="true"
+                android:focusable="true"
                 android:background="?attr/colorSurface" />
 
-            <!-- Quit button — stops all services and exits -->
-            <com.google.android.material.button.MaterialButton
-                android:id="@+id/btn_quit"
-                style="@style/Widget.Material3.Button.IconButton.Filled.Tonal"
-                android:layout_width="40dp"
-                android:layout_height="40dp"
-                android:alpha="0.7"
-                app:icon="@drawable/ic_close"
-                app:iconSize="18dp"
-                app:iconGravity="textStart"
-                app:iconPadding="0dp"
-                app:cornerRadius="20dp"
-                app:elevation="4dp"
-                app:layout_constraintTop_toTopOf="parent"
-                app:layout_constraintEnd_toEndOf="parent"
-                android:layout_marginTop="16dp"
-                android:layout_marginEnd="16dp" />
-
             <com.google.android.material.button.MaterialButton
                 android:id="@+id/fab_recenter"
                 android:layout_width="wrap_content"
@@ -115,21 +99,6 @@
 
         </androidx.cardview.widget.CardView>
 
-        <!-- Persistent MOB Button (Crucial for safety, always on top) -->
-        <com.google.android.material.floatingactionbutton.FloatingActionButton
-            android:id="@+id/fab_mob"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_margin="16dp"
-            android:clickable="true"
-            android:focusable="true"
-            android:contentDescription="Man Overboard"
-            app:srcCompat="@android:drawable/ic_dialog_alert"
-            app:backgroundTint="@color/mob_button_background"
-            app:elevation="20dp"
-            app:layout_anchor="@id/instrument_bottom_sheet"
-            app:layout_anchorGravity="top|start" />
-
         <!-- Record Track Button -->
         <com.google.android.material.floatingactionbutton.FloatingActionButton
             android:id="@+id/fab_record_track"