feat: post-signup onboarding wizard (dietary/allergen prefs, notifications, skippable) (v0.77.0)

New accounts land on a 3-step wizard after signup — welcome, dietary preferences & allergens, notification opt-in — skippable at every step, shown once via a users.onboardingCompletedAt gate in the (app) layout. Existing accounts are backfilled as already-onboarded.

Also gives the allergen-preferences step a real write path: user_allergens previously only had a GDPR-export read.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

FEATURE_AUDIT.md

@@ -71,6 +71,7 @@ Status legend: **Exists** (fully working) · **Partial** (works but with a real
 | Auto-deduct pantry on cook | Exists (closed 2026-07-24) | Both UI callers that previously hardcoded `deductFromPantry: false` (`batch-cook-dishes.tsx`, `meal-planner.tsx`) now pass `true`. The new general "Mark cooked" feature (see below) additionally exposes it as a per-cook checkbox, default checked, rather than a silent always-on. | `apps/web/app/api/v1/recipes/[id]/cooked/route.ts`, `apps/web/components/recipe/batch-cook-dishes.tsx`, `apps/web/components/meal-plan/meal-planner.tsx` |
 | Mark recipe as cooked (any recipe, not just batch-cook) | Exists (new, 2026-07-24) | A recipe can be logged as cooked any number of times — each log is a new `cookingHistory` row, no unique constraint, this was already true at the schema level, just not exposed for plain (non-batch) recipes before. New dialog on the recipe page: date (defaults today, can backdate), servings, and a deduct-from-pantry toggle (default on). Shows a "cooked N times · last DATE" indicator once logged. | `apps/web/components/recipe/{mark-cooked-dialog,mark-cooked-section}.tsx`, `apps/web/app/api/v1/recipes/[id]/cooked/route.ts` (`cookedAt` field, new) |
 | Billing/invoice details (full name, address, phone) | Exists (new, 2026-07-24) | New `userBillingDetails` table (1:1 with `users`), separate from the display `name` field. `fullName` is required by the form/API but nullable at the DB level (no backfill for existing users); address lines/city/postal code/country/phone are all optional. Lives under `Settings → Billing`, feeds future invoice generation — not wired into Stripe yet. | `packages/db/src/schema/billing.ts` (`userBillingDetails`), `apps/web/app/api/v1/users/me/billing-details/route.ts`, `apps/web/components/settings/billing-details-form.tsx` |
+| Post-signup onboarding wizard | Exists (new, 2026-07-24) | 3-step wizard (welcome → dietary/allergen prefs → notification opt-in) shown once per account, right after the app shell layout loads for a user with no `onboardingCompletedAt`. Skippable at every step; existing accounts were backfilled as already-onboarded so the wizard only appears for new signups. Also closes a real pre-existing gap: `userAllergens` had a table and a GDPR-export read, but **no write path at all** — this ships the first one. Dietary tags are a new `users.dietaryTags` jsonb column (mirrors `recipes.dietaryTags`'s 7-tag shape); neither is yet consumed by AI generation or recipe matching. | `apps/web/app/onboarding/page.tsx`, `apps/web/components/onboarding/onboarding-wizard.tsx`, `apps/web/app/api/v1/users/me/onboarding/route.ts`, `apps/web/app/(app)/layout.tsx` (redirect gate) |
 | Expiring-soon tracking | Exists | With "use it up" recipe suggestions. The leftover-expiry push/email cron only covers batch-cook dishes — plain pantry items only get an in-app badge, no reminder. | `apps/web/components/pantry/expiring-soon-suggestions.tsx`, `apps/web/app/api/internal/cron/leftover-reminders/route.ts` |
 | **Barcode scan (pantry)** | **Exists** | Real Open Food Facts API lookup by UPC/EAN | `apps/web/app/api/v1/pantry/scan/barcode` |
 | Photo scan (pantry) | Exists | Vision-model based | `apps/web/app/api/v1/pantry/scan/photo` |