[FIX]: Use column names instead of hardcoded indexes for filtering and sorting in frontend

[drkrillo]

Problem

The JavaScript code references CSV columns by index (row[1] for language, row[4] for comments). If the CSV column order changes, filtering and sorting break silently.

Desired behavior

Use the CSV header row to resolve column names dynamically instead of relying on fixed indexes. For example, look up the index of "language" and "comments" from the header at runtime.

Thoughts & Additional Info

Look at app/frontend/index.html lines 121, 127, 131, 180.