HOLD: Use "Submit" label on /new form buttons

[maebeale]

What is the goal of this PR and why is this important?

• Standardizes the submit call to action on new-record forms to read "Submit" instead of "Create <Model>"
• Gives creation screens a consistent label across the app

How did you approach the change?

• Replaced explicit "Create …" submit labels with "Submit" on forms served from /new endpoints
• For partials shared between new and edit, only the new-record branch was changed; the edit label (e.g. "Save changes" / "Update") is preserved
• Files touched:
  • forms/new.html.erb — "Create form" → "Submit"
  • payments/_form.html.erb (rendered only by payments/new) — "Create Payment" → "Submit"
  • allocations/new.html.erb — "Create Allocation" → "Submit"
  • refunds/new.html.erb — "Create Refund" → "Submit" (kept "Refund via Stripe" branch)
  • scholarships/_form.html.erb — new branch "Create scholarship" → "Submit"
  • event_registrations/_form.html.erb — new branch "Create registration" → "Submit"

Anything else to add?

• Marked HOLD pending confirmation on scope.
• Intentionally left unchanged (flagging for reviewer):
  • payments/_allocation_form.html.erb and discounts/_allocation_form.html.erb ("Create Payment"/"Create Discount") render via the custom allocation_form turbo action, not a /new route.
  • ~30 forms use bare f.button :submit (no explicit label); simple_form auto-renders these as "Create <Model>" on new / "Update <Model>" on edit. Switching those to "Submit" would require a per-form persisted? conditional in each shared partial — held off pending direction.

🤖 Generated with Claude Code

[maebeale]

🤖 From Claude: This partial is shared by new and edit, so only the non-persisted branch changes to "Submit" — the edit label ("Save changes") is intentionally preserved.