feat(nutrition): define barcode product and food capture contracts

[artiphishle]

Goal

Add first-class contracts for the Ankhorage nutrition/barcode product database so ankhorage/api-gateway and the upcoming scan app share one canonical DTO model.

This is the contract foundation for a field-scanning workflow where many people scan products in Swiss stores and submit structured nutrition data plus evidence images.

Scope

Create a new nutrition-facing contract surface, for example:

• src/nutrition/index.ts
• src/nutrition/products.ts
• src/nutrition/capture.ts
• src/nutrition/review.ts
• optional src/nutrition/common.ts

Expose it from src/index.ts and package exports as @ankhorage/contracts/nutrition.

Required concepts

Model these as serializable TypeScript types/interfaces only. No runtime dependency unless absolutely necessary.

Product identity

• NutritionBarcode
• NutritionBarcodeType = ean_8 | ean_13 | upc_a | upc_e | gtin_14 | unknown
• NutritionProductId
• NutritionProductStatus = draft | pending_review | published | rejected | archived
• NutritionDataSource = manual_scan | user_correction | open_food_facts | foodrepo_legacy | retailer_import | admin_import

Product content

• NutritionProduct
• NutritionProductSummary
• NutritionProductDetail
• NutritionFactsPer100g
• NutritionServing
• NutritionIngredientStatement
• NutritionAllergenTag
• NutritionStoreObservation
• NutritionImageEvidence

Minimum nutrients per 100g/ml:

• energyKcal
• energyKj
• proteinG
• carbohydratesG
• sugarsG
• fatG
• saturatedFatG
• fiberG
• saltG
• sodiumG

Keep fields optional where label data may be missing, but make the product barcode, product name, source, status, and timestamps explicit.

Capture workflow

• NutritionProductCaptureRequest
• NutritionProductCaptureResponse
• NutritionProductCaptureDraft
• NutritionProductCorrectionRequest
• NutritionCaptureSubmission
• NutritionCaptureSubmissionStatus = queued | needs_more_data | accepted | rejected | merged

Capture metadata should support:

• scanner/user id when authenticated
• anonymous/device id when not authenticated
• country/store chain/store label
• image evidence references
• raw OCR/manual payload
• client timestamps
• app version/platform

Review workflow

• NutritionReviewDecisionRequest
• NutritionReviewDecisionResponse
• NutritionReviewDecision = accept | reject | merge | request_changes | publish
• reviewer note and audit fields

API DTOs to support

Define request/response shapes for at least:

• GET /v1/nutrition/products/by-barcode/{barcode}
• POST /v1/nutrition/products/capture
• GET /v1/nutrition/review/submissions
• POST /v1/nutrition/review/submissions/{submissionId}/decision

Acceptance criteria

• Types are exported from @ankhorage/contracts/nutrition.
• Root export remains backwards-compatible.
• bun run build succeeds.
• Add minimal contract tests for representative objects and literal unions.
• DTO names are stable and app-facing; database row names can remain gateway-local.
• No Swiss retailer-specific hardcoding in contracts except generic store observation fields.

[artiphishle]

Implemented the first contract slice directly on main:

• added src/nutrition/common.ts
• added src/nutrition/products.ts
• added src/nutrition/capture.ts
• added src/nutrition/review.ts
• added src/nutrition/index.ts
• exported nutrition from src/index.ts
• added package subpath export @ankhorage/contracts/nutrition
• added src/nutrition/nutrition.test.ts

Notes:

• Contracts are provider-neutral and serializable only.
• No Supabase row types were added here; gateway/database mapping stays in ankhorage/api-gateway.
• I could not run bun run build/bun test from the GitHub connector, so please run those locally before closing this issue.

Next recommended step: start ankhorage/api-gateway#33 and map these DTOs to Supabase tables/views.