FAS 1b: Progressive onboarding (3-layer flow)

- Add PROGRESSIVE_ONBOARDING feature flag to KNOWN_FLAGS
- Add onboarding_step column to users table (a/b/c)
- New backend endpoints:
  - GET /v1/onboarding/status – check current step + feature flag
  - POST /v1/onboarding/quick-start – complete Step A (goal + precision)
  - POST /v1/onboarding/complete-b – complete Step B (diet, allergens, household)
  - POST /v1/onboarding/complete-c – complete Step C (health profile)
  - POST /v1/onboarding/skip – GDPR-friendly skip
- Refactor mobile onboarding screen into 3 progressive layers
- Update auth store with onboardingStep state
- Update tab layout to only block on Step A
- Update registration to set onboardingStep='a'
- Add i18n keys for Step B/C titles across all 12 locales
- Add Zod validation schemas (quickStartInputSchema, onboardingStatusSchema)
- Add tests for validation and feature flag
- Preserve existing /v1/me/onboarding for backward compatibility
- Migration: 0004_progressive_onboarding.sql

packages/validation/src/profile.ts

@@ -70,3 +70,20 @@ export const onboardingInputSchema = z.object({
     .default({ kind: "skip" }),
 });
 export type OnboardingInput = z.infer<typeof onboardingInputSchema>;
+
+/** Progressive onboarding Step A – minimal info for immediate value (FAS 1b). */
+export const quickStartInputSchema = z.object({
+  primaryGoal: z.enum(GOAL_TYPES).optional(),
+  precisionMode: z.enum(PRECISION_MODES).default("simple"),
+});
+export type QuickStartInput = z.infer<typeof quickStartInputSchema>;
+
+/** Progressive onboarding status response (FAS 1b). */
+export const onboardingStatusSchema = z.object({
+  step: z.enum(["a", "b", "c"]),
+  onboardingCompleted: z.boolean(),
+  hasHousehold: z.boolean(),
+  hasHealthProfile: z.boolean(),
+  hasPreferences: z.boolean(),
+});
+export type OnboardingStatus = z.infer<typeof onboardingStatusSchema>;