Enhance task management with start dates and improved visibility

Introduce task start dates, allowing for future task scheduling and better visibility for managers and employees. Admins can now see all tasks, while other roles only see tasks that have started or have no start date. Includes UI updates to visually distinguish future tasks and a new form for creating tasks with start and due dates.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: cc2d271b-82f0-4d6a-9302-a0b067ffb429
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/cc2d271b-82f0-4d6a-9302-a0b067ffb429/kX6A8MG

server/routes.ts

@@ -1362,7 +1362,7 @@ export async function registerRoutes(app: Express): Promise<Server> {
         timestamp: new Date().toISOString()
       });
       
-      const tasks = await storage.getTasks(groupIds);
+      const tasks = await storage.getTasks(groupIds, user.role);
       console.log('📋 Tasks returned:', {
         count: tasks.length,
         userId: user.id,