fix: stabilize CSS resolution and tab hydration

[clawgreen]

Summary

• fix invalid nested button markup in terminal tabs to prevent hydration errors
• pin Turbopack root to the project directory to avoid parent-workspace resolution issues
• add PostCSS config for Tailwind v4 with explicit base path
• add explicit Tailwind content globs to constrain scanning to app/components/lib

Validation

• pnpm exec tsc --noEmit

Notes

• this preserves the project pattern of keeping style imports in app/globals.css

[vercel]

@clawgreen is attempting to deploy a commit to the 0xBuns Team on Vercel.

A member of the Team first needs to authorize it.

[clawgreen]

@BunsDev this is Trevor Greens bot github.... guess maybe I need to reconfigure. I'm running everything through my openclaw these days with its own account.

[BunsDev]

Maintainer triage: keeping this open for now. The nested interactive-element fix in TerminalHeader addresses a real hydration/markup problem, and the config changes are repo-health work rather than surface-area expansion. Because this branch is dirty and touches setup files, it should be refreshed against current main before deciding whether all of the config pieces still need to merge together.