Add reveal-answer learning mode

[Vipe-tools]

Description

FlashLearn currently requires the user to type an answer before the correct answer is shown and evaluated.

This works well for vocabulary learning, but is less suitable for flashcards with longer answers, such as technical definitions or question-and-answer learning.

A second learning mode should be added where the user can reveal the answer without typing it.

Proposed behavior

Add a learning mode in the settings with two options:

• Type answer – current behavior
• Reveal answer – no text input is required

When Reveal answer is selected:

1. Show the question normally.

2. Display a Reveal Answer button instead of requiring text input.

3. After clicking it, show the correct answer.

4. Display two buttons:

   • Correct
   • Incorrect

5. Use this selection for the existing repetition logic.

Reason

This would make FlashLearn useful not only for vocabulary, but also for technical terms, definitions, interview preparation, and other flashcards where typing the complete answer is unnecessary or impractical.

[Vipe-tools]

A simple "I knew the answer" and "I didn't know the answer" selection after revealing the answer would probably work well.

This would also allow the existing repetition system to remain useful:

• I knew the answer → treat the card like a correct answer
• I didn't know the answer → treat the card like an incorrect answer and repeat it according to the existing repetition settings

This way, the reveal mode would not require a separate repetition system.