Clarify entry deletion on edit page

[parterburn]

Summary

• remove the ambiguous trash icon from the entry edit header
• add a red “Delete Entry” text link centered directly below the Update Entry button
• retain the existing irreversible-action confirmation
• add feature coverage for label, placement, delete method, confirmation, and icon removal

Verification

• bundle exec rspec spec/features/entries_spec.rb — 11 examples, 0 failures
• CI vm-job and CodeFactor pass
• verified the final capitalization and confirmation flow at a 390×844 mobile viewport; canceling leaves the entry intact