refactor(frontend): entity history on tailwind-variants

[Kadrian]

Emotion → tailwind migration, PR 5/6: entity history (29 files) — after this, no component uses emotion.

(entity-history + timeline — stacked on #3996, stack overview in #3992. Only the theme plumbing is left for #3998)

Main change

• every styled() block → tv(); data-driven values (badge colours, grid templates, number widths) stay inline style
• charts (TimeStratifiedChart) resolve --color-primary-500 at runtime via getCssVarColor — downstream :root overrides keep affecting them

Worth a closer look

• three tv-const/prop shadowing crashes caught (cell — would have called the data value, value, message); renamed with comments
• EventCard: media queries → min-[1800px]:/min-[2500px]: variants; its icon's width: 24px !important → w-6! (beats FaIcon's w-[initial]! via merge, like the old important)
• EntityIdsList: active/hover logic → variants; faithful (active rows never changed on hover)
• dead code removed, behaviour-identical: TheEntityId's unused active prop, Avatar's never-used blur, SpecialText's never-passed zero
• ConceptBubble.ts/TinyLabel.ts → .tsx components

Checks: biome, tsc, vitest, vite build green; generated css spot-checked (min-[1800px]:, w-6!, blur-[6px], auto-rows).