popout: never round the body below its content height

fixes #3558

quickshell/Common/Theme.qml

@@ -2238,6 +2238,12 @@ Singleton {
         return Math.round(value * s) / s;
     }
 
+    // the epsilon keeps a value already on the grid from gaining a pixel through float error
+    function pxCeil(value, dpr) {
+        const s = dpr || 1;
+        return Math.ceil(value * s - 0.001) / s;
+    }
+
     function barWidgetThickness(innerPadding, dpr) {
         return snapEven(Math.max(20, 26 + innerPadding * 0.6), dpr);
     }

quickshell/Services/CompositorService.qml

@@ -313,6 +313,11 @@ Singleton {
         }, 0, 3000);
     }
 
+    // wlr-output reports wl_fixed (1/256 steps), surfaces render at fractional-scale-v1 N/120
+    function fractionalScale(fixedScale) {
+        return Math.round(fixedScale * 120) / 120;
+    }
+
     function getScreenScale(screen) {
         if (!screen)
             return 1;
@@ -323,12 +328,12 @@ Singleton {
 
         const randrScale = randrScales[screen.name];
         if (randrScale !== undefined && randrScale > 0)
-            return Math.round(randrScale * 20) / 20;
+            return fractionalScale(randrScale);
 
         if (WlrOutputService.wlrOutputAvailable && screen) {
             const wlrOutput = WlrOutputService.getOutput(screen.name);
             if (wlrOutput?.enabled && wlrOutput.scale !== undefined && wlrOutput.scale > 0) {
-                return Math.round(wlrOutput.scale * 20) / 20;
+                return fractionalScale(wlrOutput.scale);
             }
         }
 

quickshell/Widgets/DankPopoutHost.qml

@@ -794,7 +794,7 @@ Item {
     readonly property real shadowMotionPadding: directionalRevealActive ? 0 : Math.max(0, animationOffset)
     readonly property real shadowBuffer: Theme.snap(Math.max(popoutHandle.surfacePadding, shadowRenderPadding + shadowMotionPadding), dpr)
     readonly property real alignedWidth: Theme.px(popupWidth, dpr)
-    readonly property real alignedHeight: Theme.px(popupHeight, dpr)
+    readonly property real alignedHeight: Theme.pxCeil(popupHeight, dpr)
     readonly property real surfaceBodyWidth: Math.max(alignedWidth, Theme.px(Math.min(minimumSurfaceWidth, screenWidth), dpr))
     readonly property real surfaceBodyX: Theme.snap(_standaloneAlignedXFor(surfaceBodyWidth), dpr)
     readonly property real _surfaceOriginX: connected ? 0 : _surfaceX