Rename email schema from 'emailApi' to 'email' — consistent naming convention

- Update MigrationConstants.SchemaName in email-api-data from 'emailApi' to 'email'
- All migrations automatically use the new schema name via MigrationConstants reference
- Aligns with naming convention: 'email', 'rag', 'cvMatcher', 'cvSearch', 'myAi'

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Apis/email-api-data/MigrationConstants.cs

@@ -6,6 +6,6 @@ namespace EmailApi.Data;
 /// </summary>
 public static class MigrationConstants
 {
-    public const string SchemaName = "emailApi";
+    public const string SchemaName = "email";
     public const string MigrationTableName = "_Migrations";
 }