fix: Resolve #382 - Add safe area in "New transaction" page

[xDefcon]

🎯 Description

Adds safe area padding to the bottom bar to fix overlap with system navigation in the "New transaction" page (add_page.dart).

Closes: #382

📱 Changes

• Added safe area to bottom bar (ADD TRANSACTION button)
• Bug fix for UI visibility

🧪 Testing Instructions

Behaviour

1. Open app on Android using the system's three-dot navigation bar.
2. Tap on + (new transaction) button.
3. Check bottom bar for overlap.

📸 Screenshots / Screen Recordings (if applicable)

ANDROID BEFORE: |

ANDROID AFTER:

🔍 Checklist for reviewers

• [ ] Code is formatted correctly
• [ ] Tests are passing
• [ ] New tests are added (if needed)
• [ ] Style matches the figma/designer requests
• Tested on:
  • [ ] iOS
  • [ ] Android

[bongio94]

Code changes LGTM! I haven't tested on any device tho and I can't modify the checklist

[napitek]

@xDefcon Hi, could you check the conflicts when you have time so we merge it?

[xDefcon]

@napitek Hi, I resolved the conflicts and added a new commit to adopt the updated code formatting style, which was merged after this PR was created, causing the checks to fail.

[xDefcon]

@bongio94 I think this can be merged