Fix: Never pair exclusionMode with exclusiveZone

Quickshell's exclusiveZone setter flips exclusionMode back to Normal as a
side effect, so a window declaring both is at the mercy of which property
the QML engine applies last. The 2026-09-14 Qt update changed that order
and every full-screen overlay slid under the bar.

Each overlay now declares ExclusionMode.Ignore alone. The capture picker
was the visible failure: it started under the bar, the full-output freeze
frame was squeezed into a shorter box, and every selection landed one
bar-height off in the real capture.

tests/quickshell/exclusion-idiom-contract fails any file that pairs them.

config/dot/quickshell/modules/capture/CaptureOverlay.qml

@@ -27,9 +27,13 @@ PanelWindow {
         right: true
     }
 
-    // Fullscreen overlays must not reserve space, or every window on the
-    // workspace gets resized as the picker opens and closes.
-    exclusiveZone: 0
+    // Ignore, and nothing else: reserve no space (or every window on the
+    // workspace resizes as the picker opens and closes) and respect nobody's
+    // (or the window starts under the bar, the full-output freeze frame is
+    // squeezed into a shorter box, and every selection lands one bar-height
+    // off in the real capture). Never pair this with exclusiveZone; see
+    // tests/quickshell/exclusion-idiom-contract.
+    exclusionMode: ExclusionMode.Ignore
 
     WlrLayershell.namespace: "qs-capture" // matched by a layerrule in hypr/rules.lua
     WlrLayershell.layer: WlrLayer.Overlay