test(text): cover the card-name and blurb display helpers

[Amayyas]

What

lib/text.ts runs on every card and had no tests. This adds 18, no source changes.

Same spirit as #60 — pinning pure display logic — but this module has a sharper reason to be covered: cardDisplayName isn't just a helper, it is the fix for #48 (two-word surnames vanishing from the card). Nothing guarded that fix, so a refactor could quietly bring the bug back. deEmDash rewrites the archetype blurb on the card and the OG image.

What's pinned

cardDisplayName balances one goal (show the surname) against three fallbacks, and each is nailed on both sides of its boundary — that's where the next off-by-one would hide:

• the fix(card): fix two words not displayed bug in the card #48 regression directly: a two-word surname (Guido van Rossum → van Rossum) must render in full;
• surname too long → first name, at 13 vs 14 chars;
• surname too many words → first name, at 3 vs 4 words;
• full name kept whole at 9 vs 10 chars;
• a single unsplittable word kept whole (nothing to trim to).

deEmDash: first break → ":", later breaks → ",", the -- ASCII variant, spacing normalisation (a—b and a — b both → a: b), and that dash-free copy is left untouched.

Confidence

Mutation-checked: reintroducing the #48 bug (surname = last word only) turns two of these tests red, including the one labelled for #48 — so the guard actually guards.

255 passed (+18), lint clean, build green.