[yashsarvaiya45]

Description

• Added validation guards to prevent submitting attachments with empty or whitespace-only filenames (!fileName?.trim()).
• Disabled the send button when the file name is blank to prevent accidental empty submissions from the UI.
• Added a catch block around RCInstance.sendAttachment to properly catch and log network/server upload errors, preventing unhandled promise rejections.
• Sanitized the attachment filename with .trim() prior to sending.

Testing

• Verified local code formatting and lint checks pass cleanly (yarn lint).