Add 'Mark as Cleaned Up' functionality

- Add cleaned_at and cleaned_by_user_id fields to reports table
- Create database migration for cleanup tracking
- Add markAsCleaned backend endpoint and service method
- Add Mark as Cleaned Up button to ReportDetailModal
- Update types to include cleaned fields
- Add frontend handler to mark reports as cleaned

server/prisma/migrations/20251116222516_add_cleaned_fields/migration.sql

@@ -0,0 +1,10 @@
+-- Add cleaned_at and cleaned_by_user_id fields to reports table
+ALTER TABLE `reports` 
+ADD COLUMN `cleaned_at` TIMESTAMP NULL,
+ADD COLUMN `cleaned_by_user_id` VARCHAR(36) NULL,
+ADD INDEX `idx_cleaned_at` (`cleaned_at`),
+ADD CONSTRAINT `reports_cleaned_by_fk` 
+  FOREIGN KEY (`cleaned_by_user_id`) 
+  REFERENCES `users`(`id`) 
+  ON DELETE SET NULL 
+  ON UPDATE NO ACTION;