Let crops extend past the image edges into blank padding

Crop handles can now be dragged outside the image; the extra area
applies as transparent padding (verified pixel-exact), capped at one
image dimension per side. Edges snap to the image borders within 10
points, and a Reset button in the crop bar restores the current image's
region. The crop canvas shows padding as a flat blank surface that
disappears as handles move back inside.

Generated with OpenCode

Assisted-by: Kimi:k3

build-app.sh

@@ -111,9 +111,9 @@ cat > "$APP/Contents/Info.plist" <<'PLIST'
     <key>CFBundleIconFile</key>
     <string>Icon</string>
     <key>CFBundleShortVersionString</key>
-    <string>1.12.0</string>
+    <string>1.13.0</string>
     <key>CFBundleVersion</key>
-    <string>120</string>
+    <string>130</string>
     <key>LSUIElement</key>
     <true/>
     <key>NSHighResolutionCapable</key>