[bug] Tailwind opacity modifiers aren't working

[brendan-kellam]

Describe the bug

https://v3.tailwindcss.com/docs/customizing-colors#using-css-variables

To reproduce

1. Apply a tailwind opacity modifier to a color (e.g., text-primary/80)
2. Observe that the opacity (80%) isn't actually applied

Sourcebot deployment information

Sourcebot version (e.g. v3.0.1): v4.5.1

Additional information

We need to be using just color channels in our globals.css (instead of rgb and hsl functions).
See: https://v3.tailwindcss.com/docs/customizing-colors#using-css-variables

[divyanshu-iitian]

I reproduced the config mismatch on current main: Tailwind colors resolve to complete values like var(--primary), so /80 has no alpha placeholder to apply. I'd like to fix this with a small shared color adapter in tailwind.config.ts that preserves the existing theme variables and emits color-mix(..., transparent) only when Tailwind supplies an opacity value. This avoids a broad rewrite of every light/dark token (including hex and nested var() values) and keeps colors unchanged when no modifier is used. I'll add a focused config-level regression test for text-primary/80. Please let me know if you prefer the larger raw-HSL-channel migration described in the issue.