Typography floor raise — no more squinting #1899

Scope

• app/src/theme/typography.ts: displaySm 12→14; body presets +1
• New Heading component clamping Cinzel usage ≥16px (Cinzel below that reads like a wine label)
• Audit pass on the 4 densest screens

Depends on

Hex sweep (#1898) so we're not auditing un-themed screens.