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.

docs/configuration/bindings.md

@@ -117,19 +117,23 @@ Super+BackSpace last focused window; Alt+Tab/Alt+Shift+Tab MRU switching;
 Super+Shift+S area screenshot; Print Screen whole-screen screenshot;
 Super+Shift+E logout confirmation.
 
-Hold Super and drag a floating window with the left mouse button to move it.
+Hold Super and drag a floating or tiled window with the left mouse button to move it.
 Hold Super and drag with the right mouse button to resize. The starting position
 selects an edge or corner using a 3×3 grid; the center selects the nearest corner.
 The selected edges stay fixed for the whole drag. These work even when an app has
 no title bar or resize border.
 
+Tiled drops can reorder windows, join tab groups or move between monitors.
+Mouse buttons and wheel directions can also use the regular binding actions;
+see [mouse bindings](input.md#mouse-bindings) for configuration and drag controls.
+
 For a floating window, Super+Shift+H/J/K/L moves left/down/up/right by 32 logical
 pixels. Super+Ctrl+H/L shrinks/grows its width; Super+Ctrl+K/J shrinks/grows its
 height by the same step. Keyboard adjustments respect client size limits and
 keep the window reachable in its output's work area. Fullscreen and maximized
 floating windows ignore these actions.
 
-Mouse moves and resizes snap to work-area edges and nearby visible window edges at
+Floating moves and resizes snap to work-area edges and nearby visible window edges at
 10 logical pixels, then resist movement until 20 pixels from the attached edge.
 Window edges are eligible only when the windows overlap along the other axis,
 with a 10-pixel allowance. Hold Shift during a drag to bypass snapping.