Add mouse window controls and finer display scaling (#63)

Add configurable mouse and wheel bindings, window move and resize, tab drops, cross-output dragging, and device settings. Adjust display scaling in 0.05 increments.

Preserve opposite-edge positioning during scrolling resizes and show rows for edge drops into tabbed columns.

packaging/config.kdl

@@ -61,10 +61,21 @@ input {
 
     touchpad {
         tap #true
+        accel-speed 0.0
         natural-scroll #true
         disable-while-typing #true
+        disable-while-mouse-connected #false
         swipe-threshold 80
     }
+    mouse {
+        natural-scroll #false
+        accel-speed 0.0
+        left-handed #false
+        middle-emulation #false
+        scroll-factor 1.0
+        drag-threshold 4.0
+        scroll-cooldown-ms 150
+    }
 }
 
 layout {