Remove dynamic form builder and complete RoundProject→roundId migration

Major cleanup and schema migration:
- Remove unused dynamic form builder system (ApplicationForm, ApplicationFormField, etc.)
- Complete migration from RoundProject junction table to direct Project.roundId
- Add sortOrder and entryNotificationType fields to Round model
- Add country field to User model for mentor matching
- Enhance onboarding with profile photo and country selection steps
- Fix all TypeScript errors related to roundProjects references
- Remove unused libraries (@radix-ui/react-toast, embla-carousel-react, vaul)

Files removed:
- admin/forms/* pages and related components
- admin/onboarding/* pages
- applicationForm.ts and onboarding.ts routers
- Dynamic form builder Prisma models and enums

Schema changes:
- Removed ApplicationForm, ApplicationFormField, OnboardingStep, ApplicationFormSubmission, SubmissionFile models
- Removed FormFieldType and SpecialFieldType enums
- Added Round.sortOrder, Round.entryNotificationType
- Added User.country

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/(admin)/admin/projects/[id]/edit/page.tsx

@@ -121,7 +121,7 @@ function EditProjectContent({ projectId }: { projectId: string }) {
 
   // Fetch existing tags for suggestions
   const { data: existingTags } = trpc.project.getTags.useQuery({
-    roundId: project?.roundProjects?.[0]?.round?.id,
+    roundId: project?.roundId ?? undefined,
   })
 
   // Mutations
@@ -167,7 +167,7 @@ function EditProjectContent({ projectId }: { projectId: string }) {
         title: project.title,
         teamName: project.teamName || '',
         description: project.description || '',
-        status: (project.roundProjects?.[0]?.status ?? 'SUBMITTED') as UpdateProjectForm['status'],
+        status: (project.status ?? 'SUBMITTED') as UpdateProjectForm['status'],
         tags: project.tags || [],
       })
     }
@@ -202,7 +202,7 @@ function EditProjectContent({ projectId }: { projectId: string }) {
       teamName: data.teamName || null,
       description: data.description || null,
       status: data.status,
-      roundId: project?.roundProjects?.[0]?.round?.id,
+      roundId: project?.roundId ?? undefined,
       tags: data.tags,
     })
   }