rebrand: Kasualdad LFED → Local First Education Data Framework (LFED)

feat: hide bring-back button, add CSV download, about/FAQ modal

Fix domain column layout, textarea bg, dropdown overlap

UI polish: white input boxes, thin borders, domain dropdown alignment, blurb update

tighten: contrast fixes, compact header, dropdown columns, number formatting

redesign: soft monochrome Query tab with instructions, domain starters, and one-step prior-answer memory