Hide FAB on scroll + 168dp list padding so it never overlaps cards

- Add a RecyclerView scroll listener on the profile list: hide the docked
  FAB on downward scroll, show it on upward scroll or when the list
  settles (idle). Only acts in stable Stopped/Connected states so it
  doesn't fight the FAB's connect/disconnect animation.
- Bump profile + route list bottom padding to 168dp (FAB occupies ~157dp
  at 440dpi) so the last card always rests above the docked FAB and the
  pinned stats bar, in both connected and disconnected states.

Verified on Android (Dracula-M3, connected): last card clears the FAB at
the scroll extent; FAB tucks away while scrolling.

Author: hawkff

app/src/main/java/io/nekohasekai/sagernet/ui/ConfigurationFragment.kt

@@ -1396,6 +1396,29 @@ class ConfigurationFragment @JvmOverloads constructor(
             configurationListView.adapter = adapter
             configurationListView.setItemViewCacheSize(20)
 
+            // Hide the docked FAB while scrolling down (so it never overlaps the
+            // bottom card) and bring it back on upward scroll or when the list
+            // settles. Mirrors the stats bar's hideOnScroll behavior. Only act in
+            // stable states (Stopped/Connected) so we don't fight the FAB's own
+            // show/hide animation during Connecting/Stopping.
+            configurationListView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+                private fun stableState(): Boolean = DataStore.serviceState.let {
+                    it == BaseService.State.Stopped || it == BaseService.State.Connected
+                }
+
+                override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                    if (!stableState()) return
+                    val fab = (activity as? MainActivity)?.binding?.fab ?: return
+                    if (dy > 4) fab.hide() else if (dy < -4) fab.show()
+                }
+
+                override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+                    if (newState == RecyclerView.SCROLL_STATE_IDLE && stableState()) {
+                        (activity as? MainActivity)?.binding?.fab?.show()
+                    }
+                }
+            })
+
             if (!select) {
                 undoManager = UndoSnackbarManager(activity as MainActivity, adapter!!)
                 setupItemTouchHelper()

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

@@ -10,7 +10,7 @@
     android:paddingLeft="4dp"
     android:paddingTop="4dp"
     android:paddingRight="4dp"
-    android:paddingBottom="150dp"
+    android:paddingBottom="168dp"
     android:scrollbarSize="0dp"
     app:fastScrollAutoHide="true"
     app:fastScrollThumbColor="?colorPrimary"

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

@@ -22,7 +22,7 @@
             android:paddingLeft="4dp"
             android:paddingTop="4dp"
             android:paddingRight="4dp"
-            android:paddingBottom="150dp"
+            android:paddingBottom="168dp"
             android:scrollbarSize="0dp"
             app:fastScrollAutoHide="true"
             app:fastScrollThumbColor="?colorPrimary"