Add per-window resize-margin override (Hyprland's extend_border_grab_area)

MISSING.md had listed this as needing to touch srdwm_core::window::
hit_test's signature at every call site, including the honest-stub
Windows/macOS backends - overstated on closer inspection: that shared
function already takes a plain resize_margin: i32 parameter, agnostic
to where the value comes from. The only real change needed was reading
Window.resize_margin.unwrap_or(wm-wide default) instead of always the
WM-wide value, at the single call site inside WindowManager::hit_test
in core - no backend touched at all.

Window.resize_margin: Option<i32>, WindowRuleActions.resize_margin to
match, applied in add_window/reapply_rules_if_pending the same way
opacity already is. Settable via a rule action or
srd.window.set_resize_margin(n) on the focused window.

1 files changed, 2 insertions, 1 deletions

diff --git a/crates/core/src/manager/hittest.rs b/crates/core/src/manager/hittest.rs
index 2d52b57..06ac659 100644
--- a/crates/core/src/manager/hittest.rs
+++ b/crates/core/src/manager/hittest.rs
@@ -24,7 +24,8 @@ impl WindowManager {
             if w.minimized || w.workspace != self.current_workspace {
                 continue;
             }
-            if let Some(hit) = ResizeEdge::hit_test(w.geometry, x, y, w.decorated, w.border_width, self.resize_margin) {
+            let margin = w.resize_margin.unwrap_or(self.resize_margin);
+            if let Some(hit) = ResizeEdge::hit_test(w.geometry, x, y, w.decorated, w.border_width, margin) {
                 return Some((w.id, hit));
             }
         }