Fix supersample blur and click-cancellation on micro-drags

The 3x supersample resized the whole capture (blurring content); only the
corner mask is supersampled now, applied through clip(to😷) with the
image drawn once at native scale. The tap's drag branch also clears the
hovered window on sub-4px jitter, cancelling click-to-capture; the
threshold is applied there too.

💘 Generated with Crush

Assisted-by: Crush:deepseek-v4-flash-0731

build-app.sh

@@ -108,9 +108,9 @@ cat > "$APP/Contents/Info.plist" <<'PLIST'
     <key>CFBundleIconFile</key>
     <string>Icon</string>
     <key>CFBundleShortVersionString</key>
-    <string>1.8.5</string>
+    <string>1.8.6</string>
     <key>CFBundleVersion</key>
-    <string>85</string>
+    <string>86</string>
     <key>LSUIElement</key>
     <true/>
     <key>NSHighResolutionCapable</key>