Cannot use arrow keys to navigate back or edit input during plan question flow #528

Description

During the plan creation question flow, there is no way to navigate backward to a previous question or use the cursor/arrow keys to edit your text input in the answer field.

Once you advance to the next question, there is no way to go back and revise a prior answer without restarting the entire flow.

Steps to reproduce

1. Start a new plan session
2. Answer the first question (select an option + type additional context)
3. Click "Next question" to advance
4. Try to go back to edit the previous answer — no mechanism exists (arrow keys, back button, etc.)
5. Also: within a single text input, arrow key cursor navigation may not work as expected

Expected behavior

• Arrow keys should allow cursor movement within the text input field
• There should be a way to navigate back to previous questions to edit answers before finalizing the plan

Environment

• Model: GPT-5.4
• Mode: Plan, High, Full access