Internal changes

• Add .editorconfig by @satelllte in #77
• LICENSE: 2025 by @satelllte in #80
• Tailwind v4 by @satelllte in #82
• Vitest v3 by @satelllte in #84
• Bun text-based lockfile by @satelllte in #85
• Remove redundant PostCSS dependency by @satelllte in #87
• Remove linter by @satelllte in #89
• Astro, React 19 by @satelllte in #91

Full Changelog: v0.3.3...v0.3.4