Export & Import task

[Tiya-Verma]

Pull Request Template

What?

Implemented full-stack functionality to allow users to export their recorded EEG session data to CSV files and load existing CSV data back into active web sessions.

How?

• Backend Integration & Proxy: Created two New Next.js API route handlers (/api/sessions/[session_id]/eeg_data/export & import) to securely proxy frontend requests to the Python backend API.
• API Helper Library: Added exportEEGData, importEEGData, and downloadCSV helper functions to ib/eeg-api.ts to manage API requests and handle the browser-side file downloads using Blob URLs.
• Frontend Dialog Components: Built the ExportDialog and ImportDialog
• UI Hooks via App Header: Plumbed the new components into app-header.tsx, adding the toggle state and triggering the dialogs via the "Export Data" & "Import Data" buttons.

Testing

• Uploaded a .csv datasets through the Import dialog and verified that the importEEGData function correctly posts the data payload up to the proxy endpoint.
• Tested exporting an entire session (by leaving Start and End time blank) and verified that the browser receives and correctly downloads the generated session_[id]_[timestamp].csv file.
• Ran Next.js component build checks (npx tsc) successfully.