Fix scroll offset reset due to floating-point precision errors (#677)

When the panel is already at a boundary position, floating-point
precision errors on some devices (like iPhone 17 Pro Max) can cause
unexpected offset resets in the position calculation.

This commit addresses the layout issue where fractional values caused
incorrect position evaluation. Based on the initial fix and sample
project provided by @0x1306a94.

Co-authored-by: 0x1306a94 <onyxes_accent_0a@icloud.com>

Author: scenee

Sources/Layout.swift

@@ -306,7 +306,7 @@ class LayoutAdapter {
     }
 
     func surfaceLocation(for state: FloatingPanelState) -> CGPoint {
-        let pos = position(for: state).rounded(by: surfaceView.fp_displayScale)
+        let pos = position(for: state)
         switch layout.position {
         case .top, .bottom:
             return CGPoint(x: 0.0, y: pos)
@@ -316,6 +316,10 @@ class LayoutAdapter {
     }
 
     func position(for state: FloatingPanelState) -> CGFloat {
+        return _position(for: state).rounded(by: surfaceView.fp_displayScale)
+    }
+
+    private func _position(for state: FloatingPanelState) -> CGFloat {
         let bounds = vc.view.bounds
         let anchor = layout.anchors[state] ?? self.hiddenAnchor