Add dspack contract surface to cross-surface drift analysis

[ryandmonk]

What

Adds a read-only dspack contract surface to the cross-surface drift engine. af design drift can now compare component metadata across Figma, Storybook, and code against a declared design-system contract — a dspack v0.1/v0.2 file committed to source control:

af design drift Button --dspack ./my-system.dspack.json
# or set contract.dspackPath in af.config.json

This is the first code-level integration between AF and the dspack ecosystem, completing the loop: dspack-export generate → commit the snapshot → serve it to agents via ds-mcp → AF polices it over time.

How it works

• packages/watcher/src/contractSurface/ (new): Ajv loader that validates against vendored v0.1/v0.2 schemas (pinned to dspack commit 7008c3e, provenance in schema/README.md), mirroring ds-mcp's reference loader semantics — a file that loads in ds-mcp loads here. Read-only accessors map dspack component entries into the drift engine's prop/variant vocabulary (enum values → high-confidence constrained comparisons).
• Drift engine: a new compareContractSurface() covers component presence, prop inventory vs. code, and enum-variant coverage vs. code and Figma. The three pre-existing comparison functions are untouched.
• Direction semantics: the contract declaring something a live surface lacks is genuine drift (warn); code having something the contract lacks is a staleness signal (contract-staleness:* findings, info) with a one-line remediation hint pointing at dspack-export regeneration.
• CLI: the contract counts toward the 2-surface availability gate (contract + code analysis works with Figma and Storybook down), serves as the component inventory when Storybook is unavailable, and renders a Contract ✓/✗ status segment.

Boundaries preserved

• The contract surface is deliberately not a DesignAdapter and is never registered in the adapter registry (the drift CLI treats the registry's first available adapter as the Figma surface). Rationale documented in docs/adapter-model.md.
• Surface taxonomy: classified as surfaceType: 'contract', read-only, external-non-authoritative — the descriptor layer carries no authority into reconciliation.
• Out of scope by design: token drift, CI gating/thresholds, reconciliation changes (Phase 14F precedence untouched), write paths, dspack generation, ds-mcp involvement.

Backward compatibility

Dormant by default: with no --dspack flag and no contract config key, no new code path executes. All type widenings are additive, and a regression-guard test asserts no-contract reports contain no contract keys, no contract findings, and only the three legacy surface keys.

Testing

• Full watcher suite: 1986/1986 (was 1953 before; +33 new tests, zero regressions; suite re-run after the type widening alone to prove it non-breaking in isolation)
• New: 6 loader tests, 10 mapping tests, 12 analyzer contract tests, 5 CLI e2e tests driving main() against the committed shadcn-demo fixture (copied from dspack-export's golden fixture, self-contained — no cross-repo reference at test time) and the real demos/react-demo-app code surface
• CLI package: 50/50; monorepo-wide pnpm typecheck clean
• New dependency: ajv@^8.17.0 (watcher only)

Reviewer notes

• contract-mismatch DriftType is defined but unused in this slice — reserved for value-level comparisons (e.g., default-value mismatch) in a follow-up.
• Against AF's own demo app the sample output is warn-heavy because the demo Button intentionally differs from the shadcn fixture; a demo-matched contract fixture for a "No drift detected" happy path is a candidate follow-up before announcing.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds a new read-only dspack contract surface to AF’s cross-surface drift analysis so af design drift can compare component inventories/props/enum variants across Figma, Storybook, code (AST), and an optional dspack JSON contract (v0.1/v0.2), with config + CLI flag support and comprehensive watcher tests.

Changes:

• Introduces packages/watcher/src/contractSurface/ with Ajv-based loader + vendored dspack schemas and mapping helpers to the drift engine vocabulary.
• Extends the drift engine/types to include a contract surface (DriftSurfaceId) and adds contract-aware comparisons + CLI output/inventory behavior when Storybook/Figma are unavailable.
• Adds config/docs/tests and watcher dependency updates to support the new surface end-to-end.

Reviewed changes

Copilot reviewed 28 out of 29 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
README.md	Updates CLI command description to mention dspack contract surface.
pnpm-lock.yaml	Locks new watcher dependency (ajv).
packages/watcher/src/crossSurfaceDrift/normalize.ts	Widens surface ID typing to include contract.
packages/watcher/src/crossSurfaceDrift/cliCrossSurfaceDrift.ts	Adds --dspack flag/config loading, contract+code-only mode, and reporting.
packages/watcher/src/crossSurfaceDrift/analyze.ts	Adds contract snapshot construction and contract-vs-live comparisons.
packages/watcher/src/crossSurfaceDrift/tests/contractDrift.test.ts	Unit tests for contract drift semantics + no-contract regression guard.
packages/watcher/src/crossSurfaceDrift/tests/cliContractE2e.test.ts	CLI e2e tests for --dspack behavior with live surfaces down.
packages/watcher/src/contractSurface/types.ts	Defines minimal dspack document types used by the watcher.
packages/watcher/src/contractSurface/surface.ts	Maps dspack component entries to drift SurfaceProp + derived variants.
packages/watcher/src/contractSurface/schema/README.md	Documents schema provenance and pinning strategy.
packages/watcher/src/contractSurface/schema/dspack.v0.2.schema.json	Vendored dspack v0.2 JSON schema.
packages/watcher/src/contractSurface/schema/dspack.v0.1.schema.json	Vendored dspack v0.1 JSON schema.
packages/watcher/src/contractSurface/loadContract.ts	Implements file loader + Ajv validation for dspack v0.1/v0.2.
packages/watcher/src/contractSurface/index.ts	Exposes contract surface public API (load + accessors).
packages/watcher/src/contractSurface/tests/surface.test.ts	Tests mapping/lookup rules for contract surface accessors.
packages/watcher/src/contractSurface/tests/loadContract.test.ts	Tests loader acceptance/rejection paths and error messages.
packages/watcher/src/fixtures/contract/shadcn-demo.dspack.json	Adds a committed dspack fixture for self-contained tests.
packages/watcher/src/fixtures/contract/README.md	Documents contract fixture files used by tests.
packages/watcher/src/fixtures/contract/invalid-version.dspack.json	Fixture for unsupported dspack version rejection.
packages/watcher/src/fixtures/contract/invalid-schema.dspack.json	Fixture for schema violation rejection.
packages/watcher/package.json	Adds ajv dependency (watcher-only).
packages/shared/src/surfaceMetadata.ts	Extends surface taxonomy with surfaceType: 'contract'.
packages/shared/src/crossSurfaceDrift.ts	Adds contract surface identifiers, findings fields, and contract data types.
packages/shared/src/configLoader.ts	Adds default + validation/merge support for contract.dspackPath.
packages/shared/src/config.ts	Adds config schema for contract surface (contract.dspackPath).
packages/cli/src/commands/design.ts	Updates af design drift help text to mention contract + example flag.
docs/cli-reference.md	Documents af design drift + --dspack behavior and semantics.
docs/adapter-model.md	Documents contract surface and why it is not a DesignAdapter.
claude.md	Updates repo guidance to mention contract surface constraints.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported