feat(api): add extended pet profile fields — schema, migration, CRUD, Zod validation

Adds five new nullable columns to the pets table:
- coat_type (text)
- temperament_score (integer, range 1–5)
- temperament_flags (jsonb, string[])
- medical_alerts (jsonb, typed MedicalAlert[])
- preferred_cuts (jsonb, string[])

Also:
- Exports MedicalAlert interface and MedicalAlertSeverity type from schema
- Updates shared Pet type in packages/types
- Adds Zod validators for all fields (ranges, max lengths, enum)
- Adds 14 tests covering happy path and validation edge cases
- Fixes drizzle.config.ts schema path (was ./src/schema.ts, correct is ./src/db/schema.ts)

Refs: GRO-1176

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/migrations/0030_extended_pet_profile.sql

@@ -0,0 +1,12 @@
+-- Migration: 0030_extended_pet_profile
+-- Adds extended profile fields to the pets table
+
+BEGIN;
+
+ALTER TABLE pets ADD COLUMN coat_type text;
+ALTER TABLE pets ADD COLUMN temperament_score integer;
+ALTER TABLE pets ADD COLUMN temperament_flags jsonb DEFAULT '[]'::jsonb;
+ALTER TABLE pets ADD COLUMN medical_alerts jsonb DEFAULT '[]'::jsonb;
+ALTER TABLE pets ADD COLUMN preferred_cuts jsonb DEFAULT '[]'::jsonb;
+
+COMMIT;