Template Editor: UX rework for usability

[saiko-psych]

Problem

The Template Editor is currently confusing and overwhelming for users. It needs a rework to be easier to handle.

Known Issues

• Duplicate mandatory setting — mandatory appears in two places
• Tool properties are confusing — LimeSurvey-specific settings are not clearly separated from PRISM template fields
• Language validation gaps — not fully validated whether all required content exists for a selected language
• General complexity — too many fields and options visible at once, unclear workflow

Open Questions

• What should the simplified workflow look like?
• Should advanced/tool-specific settings be hidden behind an expandable section?
• Should the editor be restructured into tabs or steps?
• How does this relate to [Feature] Rich text editor for question styling in Survey Customizer and Template Editor #10 (rich text editor) and [Bug] Survey Customizer: Array subquestions treated as top-level questions for LimeSurvey export #12 (array subquestion nesting)?

Looking for input from co-authors on the redesign direction.