fix(screenshot): make screenshot DPI aware

Author: y-schwab

lib/commands/app.ts

@@ -36,6 +36,16 @@ const GET_PAGE_SOURCE_COMMAND = pwsh$ /* ps1 */ `
 `;
 
 const GET_SCREENSHOT_COMMAND = pwsh /* ps1 */ `
+    if (-not ([System.Management.Automation.PSTypeName]'DpiAwareness').Type) {
+        Add-Type @"
+        using System.Runtime.InteropServices;
+        public class DpiAwareness {
+            [DllImport("user32.dll")] public static extern bool SetProcessDPIAware();
+        }
+"@
+    }
+    [DpiAwareness]::SetProcessDPIAware() | Out-Null
+
     if ($rootElement -eq $null) {
         $bitmap = New-Object Drawing.Bitmap 1,1
         $stream = New-Object IO.MemoryStream

test/e2e/window.e2e.ts

@@ -103,4 +103,28 @@ describe('Window and app management commands', () => {
             expect(buffer[3]).toBe(0x47); // G
         });
     });
+
+    describe('DPI scaling consistency', () => {
+        it('screenshot pixel dimensions match getWindowRect width and height', async () => {
+            const rect = await calc.getWindowRect();
+            const screenshot = await calc.takeScreenshot();
+            const buffer = Buffer.from(screenshot, 'base64');
+
+            // PNG IHDR chunk: width at bytes 16-19, height at 20-23 (big-endian uint32)
+            const pngWidth = buffer.readUInt32BE(16);
+            const pngHeight = buffer.readUInt32BE(20);
+
+            expect(pngWidth).toBe(rect.width);
+            expect(pngHeight).toBe(rect.height);
+        });
+
+        it('element rect fits within window bounds', async () => {
+            const windowRect = await calc.getWindowRect();
+            const btn = await calc.$('~num1Button');
+            const btnSize = await btn.getSize();
+
+            expect(btnSize.width).toBeLessThanOrEqual(windowRect.width);
+            expect(btnSize.height).toBeLessThanOrEqual(windowRect.height);
+        });
+    });
 });