Overhaul Color Tokens Setup w/ Extended Button

[PauloMFJ]

Overview

Reworks the design-token system into a clear two-layer model and rebuilds the Button's color API on top of it.

Tokens (packages/tokens)

• Two layers: generic roles (accent, surface, content, shadow, …) hold the real values; component-scoped sets (button-, card-, control-, atlas-, query-, radio-, …) alias them via "$role". Components reference only their own scope's tokens — nothing borrows generics or sibling scopes directly (one deliberate exception: the button control / card-action tones).
• Value forms: RGB triplet [r,g,b], triplet + alpha [r,g,b,a] (emitted as r g b / a), or "$alias".
• Generator fixes: COLORS (TS) export now carries alpha in the same r g b / a form as the CSS vars; removed a channel-array mutation bug; alpha 0 no longer rejected.
• One-off values are inlined in their component token rather than added to the global palette; pruned dead tokens.

Button

• New API: variant (flat | border) + tone (subtle, subtle-highlight, prominent, accent, accent-subtle, control, card-action).
• Each tone is a self-contained token set (base / content / border + hovers) — retune one tone without affecting others.
• Explicit per-tone border / border-hover channels (the 5 standalone tones; control / card-action excluded).
• Disabled state is derived from the active tone (dropped the separate disabled-style prop).

Docs

• AGENTS.md updated to document the role/scope layering, value forms (incl. alpha + $alias), and the one-off-inline rule.

Build

• Generated token output (packages/tokens/dist/) is no longer committed — added
  packages/tokens/.gitignore (dist/) and a root prepare script
  (pnpm run generate:tokens) so it's regenerated on install / build.

New Buttons

Prompt and Status buttons before / after:

Export button before / after:

Everything else matches existing existing styles visually.

[gemini-code-assist]

Code Review

This pull request refactors the design tokens and the Button component to enforce a strict semantic color system with component-scoped aliases. The Button component now uses predefined variant and tone props instead of inline color schemes. Two critical issues were identified in the review: a self-referential "transparent" alias in colors.json that causes infinite recursion during the build process, and a missing aria-label on an icon-only Button in control.tsx that leads to a TypeScript compilation error.

[nick-nlb]

Thanks Paolo! The refactoring of the theme looks great (as does the reworking of the button variants).. I like the separation of token layers the overall refactor introduces.

One comment to address but approved.

[nick-nlb]

Differently to the CSS version, this one resolves to the actual color rather than the name. So where the CSS file has:
` ``
--color-atlas-surface: var(--color-surface);

The TS file has 

'atlas-surface': '247 252 255',

This means that if the partner overrides --color-surface, it will affect only CSS/SCSS but not the TS versions. Let's make this resolve to the variable in the same way.
 

[PauloMFJ]

Updated TS to resolve with shared consts for any inline values - let me know if this wasn't what you were intending?