Add dueDate to reminders, remove reminder from notes

Schema changes:
- Added dueDate field to companyReminders table
- Removed reminderDate and reminderSent from notes table

Backend changes:
- Updated company-reminder.service with dueDate handling
- Added getUpcomingReminders function for dashboard
- Simplified note.service (removed reminder logic)
- Updated validators and routes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/routes/company.routes.js

@@ -13,6 +13,7 @@ router.use(authenticate);
 // Reminder summaries (must be before :companyId routes)
 router.get('/reminders/summary', companyController.getReminderSummary);
 router.get('/reminders/counts', companyController.getReminderCountsByCompany);
+router.get('/reminders/upcoming', companyController.getUpcomingReminders);
 
 // Company unread email summary
 router.get('/email-unread', companyController.getCompanyUnreadCounts);
@@ -72,7 +73,6 @@ router.post(
   validateParams(z.object({ companyId: z.string().uuid() })),
   validateBody(z.object({
     content: z.string().min(1),
-    reminderAt: z.string().optional().or(z.literal('')),
   })),
   companyController.addCompanyNote
 );
@@ -85,7 +85,6 @@ router.patch(
   })),
   validateBody(z.object({
     content: z.string().min(1).optional(),
-    reminderAt: z.string().optional().or(z.literal('').or(z.null())),
   })),
   companyController.updateCompanyNote
 );