feat(matches): add manual match creation functionality and related fields

backend/models/Match.js

@@ -127,6 +127,17 @@ const Match = sequelize.define('Match', {
         comment: 'Array of member IDs who actually played',
         field: 'players_played'
     },
+    fixtureType: {
+        type: DataTypes.STRING,
+        allowNull: false,
+        defaultValue: 'league',
+        field: 'fixture_type'
+    },
+    notes: {
+        type: DataTypes.TEXT,
+        allowNull: true,
+        field: 'notes'
+    },
 }, {
     underscored: true,
     tableName: 'match',