Migrate to Tailwind v4 to eliminate duplicate Vite installations

[AutumnsGrove]

Problem

Currently have 2 Vite installations (4.4MB duplicate) because Tailwind v3 requires jiti@^1.21.7 while everything else uses jiti@2.4.2.

Current state

All packages use Tailwind v3.4.19:

• All 10 apps (amber, aspen, billing, clearing, domains, landing, login, meadow, plant, terrarium)
• Engine library

Root cause

tailwindcss@3.4.19 has hardcoded dependency: "jiti": "^1.21.7"

This creates separate Vite peer dependency resolutions:

• vite@7.3.2(@types/node@25.6.0)(jiti@1.21.7)(tsx@4.21.0) ← Tailwind v3 context
• vite@7.3.2(@types/node@25.6.0)(jiti@2.4.2)(tsx@4.21.0) ← Everything else

Solution

Migrate entire monorepo to Tailwind v4.

Migration scope

• Update all 11 packages from v3.4.19 to v4.x
• Update Tailwind config format (v4 uses different syntax)
• Update component classes (v4 has breaking changes)
• Test all UI across all apps
• Update Prism design tokens if needed
• Verify glassmorphism patterns still work

Benefits

• ✅ Single Vite installation (saves 2.2MB)
• ✅ Faster dependency resolution
• ✅ Modern Tailwind features
• ✅ Better performance

Notes

• This is a major migration - not a quick fix
• Recommend dedicated session with fresh energy
• May require updates to custom Tailwind plugins
• Tailwind v4 is a complete rewrite with new architecture

Context

Part of monorepo cleanup effort. We went from 7→2 Vite installations by unifying @types/node and removing duplicate eslint/bits-ui. The remaining duplicate is solely due to Tailwind v3's jiti dependency.