feat: give window closing its own Pencereler tab

The window switch sat on the Upload Service page, which implied a relationship
that does not exist: closing windows needs no ABRP token, no GPS, no upload
interval, and runs in its own service whether or not uploading is on. It is now
a sixth page of the pager, between Araç and Wi-Fi.

Splitting it in two while it moved, because the new page has room the card did
not: the switch and status stay together, and the event log gets its own card,
monospaced and no longer capped at four lines.

setOffscreenPageLimit switches from a hardcoded 4 to panes.length - 1. It was
already one short of the page count and would have gone stale again here.
refreshWindowClose runs on the two-second tick and dereferences views on a page
that may not be on screen, so the pager must not be free to detach them.

Six tabs share the bar where five did. Widget.EV.NavTab already autosizes down
to a 12sp floor, so the labels shrink rather than truncate.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/src/main/res/layout/activity_main.xml

@@ -72,6 +72,16 @@
             android:text="@string/tab_vehicle"
             app:icon="@drawable/ic_tab_vehicle" />
 
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/tabWindows"
+            style="@style/Widget.EV.NavTab"
+            android:layout_width="0dp"
+            android:layout_height="64dp"
+            android:layout_weight="1"
+            android:layout_marginEnd="@dimen/spacing_sm"
+            android:text="@string/tab_windows"
+            app:icon="@drawable/ic_tab_windows" />
+
         <com.google.android.material.button.MaterialButton
             android:id="@+id/tabWifi"
             style="@style/Widget.EV.NavTab"