Fix foreign key constraint issue when creating new records

Add a SQL script to ensure the existence of a default admin user and test data, addressing the foreign key constraint violation in the 'avoirs' table caused by missing 'created_by' references.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869/2Jd7tYp

sql/fix_foreign_key_issue.sql

@@ -0,0 +1,39 @@
+-- 🔧 CORRECTION CONTRAINTE FOREIGN KEY
+-- Le problème : l'utilisateur référencé n'existe pas !
+
+-- ÉTAPE 1: Voir les utilisateurs existants
+SELECT 'UTILISATEURS EXISTANTS' as check_type;
+SELECT id, username, role FROM users ORDER BY id;
+
+-- ÉTAPE 2: Si aucun utilisateur, créer un utilisateur admin
+INSERT INTO users (id, username, email, role) 
+VALUES ('admin', 'admin', 'admin@test.com', 'admin')
+ON CONFLICT (id) DO NOTHING;
+
+-- ÉTAPE 3: Insérer supplier et group de test si nécessaire
+INSERT INTO suppliers (name) VALUES ('Test Supplier') ON CONFLICT DO NOTHING RETURNING id;
+INSERT INTO groups (name) VALUES ('Test Group') ON CONFLICT DO NOTHING RETURNING id;
+
+-- ÉTAPE 4: Test avoir avec utilisateur existant
+INSERT INTO avoirs (
+    supplier_id, 
+    group_id, 
+    created_by,
+    invoice_reference,
+    amount,
+    comment
+) VALUES (
+    (SELECT id FROM suppliers WHERE name = 'Test Supplier' LIMIT 1),
+    (SELECT id FROM groups WHERE name = 'Test Group' LIMIT 1),
+    (SELECT id FROM users WHERE role = 'admin' LIMIT 1),  -- Utilise un ID qui existe !
+    'TEST-FK-FIXED',
+    99.99,
+    'Test après correction foreign key'
+) RETURNING id, created_by;
+
+-- ÉTAPE 5: Vérification
+SELECT 'RÉSULTAT INSERTION' as check_type;
+SELECT COUNT(*) as total_avoirs FROM avoirs;
+
+-- ÉTAPE 6: Nettoyage du test
+DELETE FROM avoirs WHERE invoice_reference = 'TEST-FK-FIXED';