Checkpoint: Ajout de la page de gestion des attestations de formation

Fonctionnalités :
- Configuration par formation (génération auto/manuel, envoi auto/manuel)
- Affichage de la liste des apprenants inscrits
- Upload de documents PDF par apprenant (mode manuel)
- Boutons de prévisualisation et d'envoi manuel
- Gestion complète des attestations

Corrections :
- Ajout des colonnes modeAttestation et modeEnvoi dans la table formations
- Ajout des colonnes documentUrl, documentS3Key, uploadedBy, uploadedAt, emailEnvoye, dateEnvoiEmail dans la table attestations
- Correction de l'erreur SQL en retirant la colonne urlPdf inexistante de la requête

.manus/db/db-query-1768248196150.json

@@ -0,0 +1,52 @@
+{
+  "query": "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'attestations' AND TABLE_SCHEMA = DATABASE();",
+  "command": "mysql --batch --raw --column-names --default-character-set=utf8mb4 --host gateway02.us-east-1.prod.aws.tidbcloud.com --port 4000 --user 4CrrYuB5tme73Qo.root --database 7PAT67UmWoxv8vwp8Bbcv6 --execute SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'attestations' AND TABLE_SCHEMA = DATABASE();",
+  "rows": [
+    {
+      "COLUMN_NAME": "id"
+    },
+    {
+      "COLUMN_NAME": "inscriptionId"
+    },
+    {
+      "COLUMN_NAME": "apprenantId"
+    },
+    {
+      "COLUMN_NAME": "sequenceId"
+    },
+    {
+      "COLUMN_NAME": "s3Key"
+    },
+    {
+      "COLUMN_NAME": "pdfUrl"
+    },
+    {
+      "COLUMN_NAME": "dateGeneration"
+    },
+    {
+      "COLUMN_NAME": "emailEnvoye"
+    },
+    {
+      "COLUMN_NAME": "dateEnvoiEmail"
+    },
+    {
+      "COLUMN_NAME": "createdAt"
+    },
+    {
+      "COLUMN_NAME": "documentUrl"
+    },
+    {
+      "COLUMN_NAME": "documentS3Key"
+    },
+    {
+      "COLUMN_NAME": "uploadedBy"
+    },
+    {
+      "COLUMN_NAME": "uploadedAt"
+    }
+  ],
+  "messages": [],
+  "stdout": "COLUMN_NAME\nid\ninscriptionId\napprenantId\nsequenceId\ns3Key\npdfUrl\ndateGeneration\nemailEnvoye\ndateEnvoiEmail\ncreatedAt\ndocumentUrl\ndocumentS3Key\nuploadedBy\nuploadedAt\n",
+  "stderr": "",
+  "execution_time_ms": 62
+}