Custom Width: Improve Sync Prompt Width functionality

[itsmartashub]

Current Behavior

• Chat width: 49rem
• Prompt field: 48rem
• Issue: Visible 1rem misalignment between Chats and Prompt Field but all the custom width fn works as it should

Tried

• Chat width default changed from 49rem to 48rem
• Prompt field syncs automatically when widths match
• Users must manually uncheck to disable syncing

Problem w/ "Tried"

Automatic width syncing creates unexpected behavior when widths happen to match, even if user hasn't enabled sync feature.

Proposed Solution

• Maintain 48rem chat width default
• Only sync prompt field width when user explicitly enables Sync with Chat option
• Keep widths independent by default, regardless if they match
• Add proper initialization to prevent auto-sync on load even if the user doesn't enable the auto-sync (it's because of the way how I'm currently maintaining the sync value like if chats width and prompt field are the same, automaticaly make it sync, and it's wrong)

Technical Changes Needed

1. Update default chat width to 48rem
2. Modify sync logic to only activate on explicit user action and update storage width settings object to attach this isSyncEnabled prop
3. Initialize sync state as false despite matching widths

Testing Notes

• Verify prompt width remains independent until sync enabled
• Confirm manual sync toggle works correctly
• Test different width combinations and page refresh