input: implement follow_mouse_shrink (#13707)

* input: implement follow_mouse_shrink

Add a new config option `input:follow_mouse_shrink` (INT, 0-300, default 0)
that shrinks inactive window hitboxes by the specified number of pixels for
focus detection purposes. This creates a dead zone in gaps between windows
where moving the cursor will not trigger a focus change.

The shrink only applies to inactive (non-focused) windows and only during
mouse-move focus checks (follow_mouse = 1). Click and scroll interactions
are unaffected — clicking on a window in the shrunk area still works
normally once the window is focused.

Closes #9973

* tests: add integration test for follow_mouse_shrink

1 files changed, 2 insertions, 1 deletions

diff --git a/src/managers/input/InputManager.cpp b/src/managers/input/InputManager.cpp
index 95e7704a..c4df7c53 100644
--- a/src/managers/input/InputManager.cpp
+++ b/src/managers/input/InputManager.cpp
@@ -419,7 +419,8 @@ void CInputManager::mouseMoveUnified(uint32_t time, bool refocus, bool mouse, st
     PHLWINDOW  pWindowIdeal;
     const auto getWindowIdeal = [&]() -> const PHLWINDOW& {
         if (!windowIdealQueried) {
-            pWindowIdeal       = g_pCompositor->vectorToWindowUnified(mouseCoords, Desktop::View::RESERVED_EXTENTS | Desktop::View::INPUT_EXTENTS | Desktop::View::ALLOW_FLOATING);
+            pWindowIdeal = g_pCompositor->vectorToWindowUnified(
+                mouseCoords, Desktop::View::RESERVED_EXTENTS | Desktop::View::INPUT_EXTENTS | Desktop::View::ALLOW_FLOATING | Desktop::View::FOLLOW_MOUSE_CHECK);
             windowIdealQueried = true;
         }