Extract the design system to @robomous/ui-core

[JArmandoAnaya]

What moved

The design system — 21 shadcn Nova primitives with their snapshots, the lib/ helpers (cn, inlineLink, menuSurface, twoLineTrigger, progressAria), statusTone, the foundation tokens/stylesheet (shadcn preset + brand), the shadcn tooling, and the design-system gates — now lives in Robomous/ui-core, published as @robomous/ui-core@0.1.0.

Re-export strategy: public API unchanged

@visionset/ui-core re-exports the whole package surface (export * from "@robomous/ui-core"), so every previously importable name still imports from the same place. LIGHT_THEME/DARK_THEME are re-exported as the merged view (foundation + extensions), so callers reading LIGHT_THEME.stage keep working unchanged.

Extension layering

VisionSet keeps what is VisionSet's: stage, the three origin-* marks, and the shell's four layout tokens, declared in the extension styles.css (which imports the foundation stylesheet first) and mirrored by the extension tokens.ts — shadcn's own extension convention, gated.

Gate split

• Travelled with the primitives (run in Robomous/ui-core): canonical snapshot gate, variant/size rosters, helper self-tests.
• Stayed here as consumer gates over @robomous/ui-core/gates: frontend/ui-core/src/tokens.test.ts (extension agreement, no foundation shadowing, merged view lost nothing), tests/scripts/design_system.test.mjs (vocabulary discipline over our own sources), and a thinned tests/scripts/design_tokens.test.mjs (coloured classes, brand sites, retired declarations, icon set, tailwind-config refusal).

Cool-down exclusion

@robomous/ui-core is added to minimumReleaseAgeExclude: it is first-party, released from our own CI minutes before it is consumed here — the supply-chain cool-down guards third-party releases.

Verification performed

• check.sh --fast PASSED (python, frontend, generated) against the published package.
• Full vitest: 1071 annotator + 1335 ui-core + 11 app; script gates 122/122.
• Browser suites: real-server cycle passed; chromium e2e 275/275.
• Pixel identity, machine-verified: darwin visual baselines generated from main's rendering, then the branch's visual suite run against them — 10/10 pass (Projects, Schema, Models, open menu, annotator; both themes).
• Violation smokes fired in both repos (canonical + colour gates in ui-core; status-palette consumer gate here), then reverted.
• Packaging validated by tarball dry-run before publishing; it caught and fixed two packaging bugs in the package repo (ESM .js extensions in dist, missing type declarations for ./gates).