Attributes lost when splitting a polygon during Edit Geometry before saving

Description
When recording a new polygon, filling in attributes, and then using "Edit Geometry" → Split before saving the feature, the entered attribute data is lost. Both resulting polygons have blank attributes even when a hard NOT NULL constraint is set. Default values are applied to only one of the resulting features.

Environment
[x] Staging
[ ] PROD

Application (+ app version, build, operating system)

• Android app: 2026.3.0 (Pixel 9, Android 16)
• iOS app: 2026.3.0 (iOS 26.0)

Steps to reproduce

1. Open a project with a polygon layer that has NOT NULL constraints and/or default values configured
2. Start recording a new polygon
3. Fill in the attribute form with valid values
4. Tap "Edit Geometry" (before saving the feature)
5. Use the Split tool to split the polygon into two parts
6. Observe the resulting features and their attributes

Actual results

• Attribute data entered in step 3 is lost — both resulting polygons have blank attributes
• One polygon is temporarily highlighted in yellow
• Hard NOT NULL constraints are not enforced (form allows blank values)
• Default values are applied to only one of the two resulting features, not both

Expected results

• Attributes entered before the split should be preserved and copied to both resulting polygons
• NOT NULL constraints should be enforced on both features
• Default values should be applied consistently to both resulting features

Screenshots or logs

https://github.com/user-attachments/assets/11de02b8-9d78-4c84-9cb5-331194b7e2ab

Conclusion
Created by Claude and supervised by a human test analyst.

Start by reproducing the split workflow on the stated Android and iOS versions with polygon layers using NOT NULL constraints and default values. Trace how entered attributes, constraints, and defaults are handled when a new polygon is split; done means both resulting polygons preserve the entered values, enforce constraints, and receive defaults consistently.