Enable duplicating closed projects with new planned end dates

Update project restarting logic to create a duplicate of a closed project, assign it a new ID, reset its status to 'planning', and set a new planned end date. The original project remains closed.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ceced2fc-aa46-458d-ba87-ddd4b7bb1518
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/659922a9-0087-461c-90dd-6d9a58b81d4d/ceced2fc-aa46-458d-ba87-ddd4b7bb1518/P2PZNJ9

client/src/components/ProjectTemplate.tsx

@@ -229,23 +229,34 @@ export default function ProjectTemplate({
 
   const handleConfirmRestart = () => {
     if (restartingProject && newEndDate) {
-      const restartedProject: Project = {
+      // Create a new project as a duplicate/copy of the closed project
+      const newProjectId = Date.now().toString();
+      
+      const duplicatedProject: Project = {
         ...restartingProject,
-        status: 'planning',
-        startDate: new Date(),
-        endDate: newEndDate,
-        tasks: clearHistory ? [] : restartingProject.tasks.map(task => ({ ...task, status: 'todo' as const }))
+        id: newProjectId, // New unique ID
+        status: 'planning', // Start as planning
+        startDate: new Date(), // Set new start date
+        endDate: undefined, // Clear end date since it's active again
+        plannedEndDate: newEndDate, // Set the new planned end date
+        createdAt: new Date(), // Set new creation date
+        tasks: clearHistory 
+          ? [] 
+          : restartingProject.tasks.map(task => ({
+              ...task,
+              id: `${newProjectId}-task-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`, // Generate new task ID
+              status: 'todo' as const // Reset all tasks to todo status
+            }))
       };
       
-      setProjects(projects.map(p => 
-        p.id === restartingProject.id ? restartedProject : p
-      ));
+      // Add the new project to the projects array without removing the original
+      setProjects([...projects, duplicatedProject]);
       
       setIsRestartProjectOpen(false);
       setRestartingProject(null);
       setNewEndDate(undefined);
       setClearHistory(false);
-      console.log('Project restarted:', restartedProject.name, 'Clear history:', clearHistory);
+      console.log('Project duplicated:', duplicatedProject.name, 'with', duplicatedProject.tasks.length, 'tasks. Original project remains closed.');
     }
   };