Fix AIChat input width on panel expand to be responsive

[OmarSalouss]

Checklist

• yarn typecheck
• yarn lint:fix
• yarn test
• yarn brl
• yarn changeset
• ui changelog

Description

Fixes an issue where the assistant input field does not expand to full width when the AIChat panel is expanded.
In the expanded state, the input container was constrained by a max-w-[700px], causing unused empty space on the right and preventing users from typing in that area.

This change removes the max-width constraint so the input properly fills the available space.

Before: input does not span the full width (see screenshot)

After: input expands correctly and is fully writable

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Latest commit: 46b96f5

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Project	Deployment	Review	Updated (UTC)
plate	Ready	Preview, Comment	Jan 20, 2026 10:11am