Chore: Machine readable design system

[TeddyCr]

Describe your changes:

Summary

Turns the existing design system into an enforced, LLM-readable token layer and migrates the entire UI CSS/LESS surface onto it. Migration is value-preserving (exact color matches, rem→px exact at the 16px root) — no intended
visual change.

What's in it

• src/styles/tokens.css — 3-layer tokens: Layer 1 --ds-* primitives → upstream globals.css with raw fallbacks; Layer 2 --om-* aliases (colors, spacing, type, radius, elevation, z-index, motion); components reference only Layer 2.
  Loaded globally via styles/index.ts.
• Migration — 369 .less/.css files, ~4.7k raw values → var(--om-*) (4,480 usages). Property-scoped and safe: url()/data-URIs, comments, LESS @vars/color-functions/arithmetic, and vendored files are never touched.
• specs/ — 22 markdown specs: 6 foundations, a generated token-reference.md (797 tokens), and 14 component specs.
• Tooling (scripts/) — token-audit (CI lint, exit 1 on hardcoded colors/spacing), token-migrate (idempotent codemod), token-gen (regenerate tokens + reference), token-drift (generated-file freshness + undefined-token +
  broken-spec-link gate), plus an engine unit-test suite. Wired as yarn scripts.
• pre-commit — token-audit (changed files) and token-drift (on style/spec changes) hooks.
• CLAUDE.md — mandates reading specs/, using only tokens.css tokens, and running token-audit (zero errors) before commit.

Verification

• yarn token-audit: 0 errors, 0 warnings
• All 369 changed files compile under the project's LESS config (math: always) — 0 regressions vs base (verified by before/after compile-diff)
• Codemod idempotent; every var(--om-/--ds-) reference is defined; 27 engine unit tests pass

Notes

• variables.less remains the legacy LESS bridge (existing @var usage is still valid); prefer var(--om-*) for new work.
• Contributors need pre-commit install once (same as existing Java/ruff hooks).

Type of change:

• Bug fix
• Improvement
• New feature
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation

High-level design:

N/A — small change.

Tests:

Use cases covered

Unit tests

Backend integration tests

Ingestion integration tests

Playwright (UI) tests

Manual testing performed

UI screen recording / screenshots:

Not applicable.

Checklist:

• I have read the CONTRIBUTING document.
• My PR title is Fixes <issue-number>: <short explanation>
• My PR is linked to a GitHub issue via Fixes #<issue-number> above.
• I have commented on my code, particularly in hard-to-understand areas.
• For JSON Schema changes: I updated the migration scripts or explained why it is not needed.
• For UI changes: I attached a screen recording and/or screenshots above.
• I have added tests (unit / integration / Playwright as applicable) and listed them above.

[greptile-apps]

Too many files changed for review. (411 files found, 100 file limit)

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[github-actions]

❌ PR checklist incomplete

This PR cannot be merged until the following are addressed on its linked issue:

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[github-actions]

Jest test Coverage

UI tests summary

Lines	Statements	Branches	Functions
	65.67% (76785/116918)	49.52% (46066/93018)	50.76% (13891/27364)

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