feat: profile flow — Zod schema, /me/profile API, /profile page with BMR/TDEE

@ketopath/shared — new module profile/schema:
- profileInputSchema (Zod): age 18-110, gender, height 120-230 cm, weights
  35-300 kg, activityLevel, optional targetDate
- GENDERS / ACTIVITY_LEVELS string-literal arrays for UI iteration
- Re-exported from @ketopath/shared

apps/api — new module modules/profile:
- PUT /me/profile: requireAuth, validates body via profileInputSchema, upserts
  the row, returns the saved profile + derived { bmr, tdee, activityMultiplier }
  (BMR/TDEE computed via @ketopath/shared)
- GET /me/profile: requireAuth, returns the same shape, 404 when missing
- Decimal columns serialised back as numbers

apps/web — new /profile page:
- src/app/[locale]/profile/page.tsx (server): redirects unauthenticated users
  to /sign-in, calls fetchProfile to hydrate the form
- profile-form.tsx (client): react-hook-form + zodResolver bound to the same
  shared schema, native styled selects for gender/activityLevel until shadcn
  Select arrives, post-submit panel showing BMR/TDEE/multiplier
- actions.ts: server actions saveProfile / fetchProfile that proxy the call
  to API_URL via cookie passthrough (no CORS, no exposed token)
- Home page gains a "Completa il tuo profilo" CTA when signed in
- API_URL env var added to .env.example
- Italian copy in messages/it.json under Profile

Verified end-to-end with the "Michele" PRD persona (49, M, 170cm, 76kg, SEDENTARY):
BMR = 1583 kcal, TDEE = 1899 kcal, multiplier 1.2 — matches the unit tests.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/shared/src/index.ts

@@ -1,3 +1,4 @@
 export * from './nutrition/bmr.js';
 export * from './nutrition/tdee.js';
 export * from './nutrition/types.js';
+export * from './profile/schema.js';

packages/shared/src/profile/schema.ts

@@ -0,0 +1,18 @@
+import { z } from 'zod';
+
+export const GENDERS = ['MALE', 'FEMALE', 'OTHER'] as const;
+export const ACTIVITY_LEVELS = ['SEDENTARY', 'LIGHT', 'MODERATE', 'INTENSE'] as const;
+
+export const profileInputSchema = z.object({
+  age: z.coerce.number().int().min(18, 'Devi avere almeno 18 anni').max(110),
+  gender: z.enum(GENDERS),
+  heightCm: z.coerce.number().int().min(120).max(230),
+  weightStartKg: z.coerce.number().min(35).max(300),
+  weightCurrentKg: z.coerce.number().min(35).max(300),
+  weightGoalKg: z.coerce.number().min(35).max(300),
+  activityLevel: z.enum(ACTIVITY_LEVELS),
+  targetDate: z.coerce.date().optional(),
+});
+
+export type ProfileInput = z.input<typeof profileInputSchema>;
+export type ProfileInputParsed = z.output<typeof profileInputSchema>;