1.4.0 - sharp corners, teal borders, Helvetica, editorial type

[asubowo]

Summary

• --radius: 0rem — sharp corners across all components
• --border + --input → teal for on-brand input/card borders
• --font-sans → Helvetica Neue stack
• Lightened all shadows (card reads as document panel, not floating bubble)
• CardTitle — uppercase font-black tracking-tight
• CardDescription — uppercase small-caps tracking treatment
• Fixed --radius-xl in @theme inline so Card's hardcoded rounded-xl doesn't override global 0

Test plan

• Login page: cream background, white card, teal borders, sharp corners, Helvetica, heavy uppercase title
• CI passes and v1.4.0 release is cut