Fix chat message alignment

[abrar-deakin]

Changes made:
Aligned sent messages to the right
Aligned received messages to the left
Improved message bubble styling for better UI consistency
Applied proper spacing and layout for chat rows
Testing:
Verified UI in emulator
Messages now display correctly based on sender

[Krisha190235]

can you please provide some screenshots ?

[Krisha190235]

Hey — tested #333 on top of #311. Both users' messages render on the right with the same dark bubble; the other person should be on the left. MessagesScreen.tsx decides alignment by sender role instead of "is this me?".

[abrar-deakin]

Tested the messaging feature using both guard and employer accounts.

Guard messages are displayed on the left side, while employer messages are displayed on the right side correctly. The sender-based alignment issue is now fixed and working as expected.