Update condition handling in FalukantService and syncDatabase utility for legacy data

- Enhanced condition processing in FalukantService to clamp values between 0 and 100, ensuring UI displays valid data.
- Implemented database cleanup in syncDatabase utility to set NULL conditions to 100 and clamp out-of-range values, improving data integrity.

backend/migrations/20251222000000-fix-vehicle-condition-null.cjs

@@ -0,0 +1,60 @@
+/* eslint-disable */
+module.exports = {
+  async up(queryInterface, Sequelize) {
+    // Ensure column exists
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      ADD COLUMN IF NOT EXISTS condition integer;
+    `);
+
+    // Backfill nulls (legacy data)
+    await queryInterface.sequelize.query(`
+      UPDATE falukant_data.vehicle
+      SET condition = 100
+      WHERE condition IS NULL;
+    `);
+
+    // Clamp out-of-range values defensively
+    await queryInterface.sequelize.query(`
+      UPDATE falukant_data.vehicle
+      SET condition = GREATEST(0, LEAST(100, condition))
+      WHERE condition < 0 OR condition > 100;
+    `);
+
+    // Default + NOT NULL
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      ALTER COLUMN condition SET DEFAULT 100;
+    `);
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      ALTER COLUMN condition SET NOT NULL;
+    `);
+
+    // Check constraint 0..100
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      DROP CONSTRAINT IF EXISTS vehicle_condition_0_100_chk;
+    `);
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      ADD CONSTRAINT vehicle_condition_0_100_chk
+      CHECK (condition >= 0 AND condition <= 100);
+    `);
+  },
+
+  async down(queryInterface, Sequelize) {
+    // Keep the column, but remove constraint/default to be reversible
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      DROP CONSTRAINT IF EXISTS vehicle_condition_0_100_chk;
+    `);
+    await queryInterface.sequelize.query(`
+      ALTER TABLE falukant_data.vehicle
+      ALTER COLUMN condition DROP DEFAULT;
+    `);
+    // NOT NULL not reverted to avoid introducing NULLs on rollback; can be adjusted if needed
+  },
+};
+
+