fix: respect RTL text direction in file attachment containers (#19891)

Fixes #19742 where file attachment containers did not inherit the chat direction setting, causing layout issues when typing in RTL languages like Persian.

Added dir={$settings?.chatDirection ?? 'auto'} to file container divs in:
- MessageInput.svelte (chat input file attachments)
- UserMessage.svelte (user message file display)
- ResponseMessage.svelte (response message file display)
- channel/Messages/Message.svelte (channel message file display)

The fix ensures file containers automatically detect and respect RTL text direction, maintaining proper layout alignment for RTL languages while preserving LTR behavior for Latin text.

src/lib/components/chat/MessageInput.svelte

@@ -1139,7 +1139,10 @@
 							{/if}
 
 							{#if files.length > 0}
-								<div class="mx-2 mt-2.5 pb-1.5 flex items-center flex-wrap gap-2">
+								<div
+									class="mx-2 mt-2.5 pb-1.5 flex items-center flex-wrap gap-2"
+									dir={$settings?.chatDirection ?? 'auto'}
+								>
 									{#each files as file, fileIdx}
 										{#if file.type === 'image'}
 											<div class=" relative group">