feat: api routes, data fetching, and forms

[HelderMendes]

Adds API routes for creating and editing core entities, along with the corresponding frontend forms, data hooks, and type definitions.

New API routes

• datasets/upload — handle dataset file uploads
• datasets/[id]/tags — manage dataset tags
• datasets/[id]/edit — update dataset metadata
• tasks/create — create new tasks
• collections/create — create collections/studies

Forms

• DatasetUploadForm — multi-field form for uploading datasets
• DatasetEditForm — edit existing dataset metadata
• TaskCreateForm — define and submit new tasks
• CollectionCreateForm — create studies/collections

Data hooks

• useDatasetStats — fetches dataset statistics
• useParquetData — fetches and parses Parquet file data
• useOpSpeed — dev-only hook for monitoring render performance and timing code blocks

Types

• Expanded type definitions for Measure, Task, and NextAuth session

Backend (outside app-next/ - requires extra attention)
server/data/views.py — replaced @jwt_required() with direct API key auth on the /data-upload endpoint. This was necessary because Next.js has no access to Flask JWT tokens. The change was discussed and agreed with Joaquin and Pieter on Slack.

Dev tools

• api/(dev)/debug-env (it should be removed)— This endpoint reads process.env directly returns empty values because of our runtime config pattern. To verify environment variables, use window.ENV in the browser console instead.