feat(ui): attach large text pastes as virtual files

Offer to turn sufficiently large plain-text clipboard pastes into
pasted-context-N.txt attachments instead of inserting them into the
composer, with ask/attach/inline composer settings.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/components/sections/openchamber/OpenChamberPage.tsx

@@ -206,6 +206,7 @@ const ChatSectionContent: React.FC = () => {
                 'followUpBehavior',
                 'persistDraft',
                 'inputSpellcheck',
+                'largeTextPaste',
             ]}
         />
     );