174: add address option to class creation

[talfee]

No description provided.

[greptile-apps]

Greptile Summary

This PR makes the class location field optional during class creation/editing. It relaxes the locationType validation in the form schema from required to nullish (aligning with the existing UpdateClass API schema), removes the required marker from the Location UI field, and updates placeholder/description text to better guide users ("Zoom link" for online, "address" for in-person).

• locationType in ClassEditSchema changed from LocationTypeEnum (required) to LocationTypeEnum.nullish(), matching the API's UpdateClass schema
• Removed the required prop from the Location form field, making it optional for class creators
• Updated description and in-person placeholder text for clearer UX guidance

Confidence Score: 5/5

• This PR is safe to merge with minimal risk — small, well-scoped changes to validation and UI text.
• The changes are minimal and well-aligned with existing patterns. The schema change matches the API schema (UpdateClass already uses nullish()), the form always initializes locationType with a default value via classToFormValues, and the remaining changes are cosmetic text updates. No logic bugs or type-safety issues found.
• No files require special attention.

Important Files Changed

Filename	Overview
src/components/classes/edit/content/class-general-section.tsx	Cosmetic changes: removed required from Location field, updated description text and placeholder for in-person location. No logic changes.
src/components/classes/edit/schema.ts	Made locationType nullish in the form schema, aligning it with the UpdateClass API schema. The form always initializes with a default value via classToFormValues.

_{Last reviewed commit: 58d6368}