feat: add portable Windows zone manager

README.md

@@ -10,6 +10,8 @@ menu entry, or registry settings.
 ## What FancyWin does
 
 - Snaps a dragged window into the zone beneath the mouse pointer.
+- Shows a transparent, click-through guide with every zone's outline and name
+  while Shift-dragging.
 - Moves the focused window between zones with keyboard shortcuts.
 - Supports different layouts for different monitors.
 - Uses percentages, so layouts adapt to resolution, orientation, display
@@ -17,10 +19,10 @@ menu entry, or registry settings.
 - Reloads its configuration automatically after the YAML file changes.
 - Lets you exclude applications that should never be moved.
 
-FancyWin is a window-moving backend rather than a complete PowerToys
-replacement. It does not display a zone overlay or include a visual layout
-editor. It also does not currently remember application positions, combine
-multiple zones, or assign layouts per virtual desktop.
+FancyWin is a focused window manager rather than a complete PowerToys
+replacement. It does not include a visual layout editor and does not currently
+remember application positions, combine multiple zones, or assign layouts per
+virtual desktop.
 
 ## Getting started
 
@@ -78,6 +80,12 @@ version: 1
 gap: 8
 shift_drag: true
 
+overlay:
+  enabled: true
+  color: "#00AEEF"
+  opacity: 90
+  border_width: 3
+
 layouts:
   - monitor: "*"
     zones:
@@ -118,10 +126,35 @@ use.
 | `version` | Configuration format. This must currently be `1`. |
 | `gap` | Inward spacing, in pixels, applied to every edge of every zone. Valid range: `0`–`500`. |
 | `shift_drag` | Enables or disables mouse snapping when Shift is held at the end of a drag. |
+| `overlay` | Controls the transparent zone guide shown during Shift-dragging. |
 | `layouts` | One or more monitor layouts containing zones. |
 | `excluded_apps` | Applications FancyWin must not move. May be empty. |
 | `hotkeys` | Global keyboard shortcuts. May be empty. |
 
+### Zone overlay
+
+The overlay appears after a window has begun moving and Shift is held. It shows
+all zones on the monitor beneath the pointer, using the same gap-adjusted
+rectangles that windows snap into. Each outline contains the zone's `name`, or
+`Zone N` when its name is empty. Releasing Shift or the mouse button immediately
+hides it.
+
+```yaml
+overlay:
+  enabled: true
+  color: "#00AEEF"
+  opacity: 90
+  border_width: 3
+```
+
+- `enabled` turns the guide on or off.
+- `color` is an outline and label color in `#RRGGBB` format.
+- `opacity` is from `1` to `100` percent.
+- `border_width` is from `1` to `20` physical pixels.
+
+The guide is transparent between its outlines, does not receive mouse input,
+does not take keyboard focus, and does not appear in Alt+Tab.
+
 ### Zone coordinates
 
 Each zone is a rectangle described as percentages of the monitor's usable work
@@ -296,6 +329,14 @@ borders, but it cannot override size rules imposed by the application itself.
 Wait at least two seconds and check the console. FancyWin keeps using the last
 valid configuration when a new edit cannot be parsed or validated.
 
+### The zone overlay does not appear
+
+- Confirm `overlay.enabled` and `shift_drag` are both `true`.
+- Begin moving the window before expecting the guide; a stationary Shift-click
+  is intentionally ignored.
+- Keep Shift held during the drag.
+- Check the console for `cannot show zone overlay` errors.
+
 ## Project relationship
 
 FancyWin is an independent implementation and does not contain Microsoft