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/server/routers/mentor.ts

@@ -410,7 +410,7 @@ export const mentorRouter = router({
       // Get projects without mentors
       const projects = await ctx.prisma.project.findMany({
         where: {
-          roundProjects: { some: { roundId: input.roundId } },
+          roundId: input.roundId,
           mentorAssignment: null,
           wantsMentorship: true,
         },
@@ -549,17 +549,10 @@ export const mentorRouter = router({
       include: {
         project: {
           include: {
-            program: { select: { name: true, year: true } },
-            roundProjects: {
+            round: {
               include: {
-                round: {
-                  include: {
-                    program: { select: { name: true, year: true } },
-                  },
-                },
+                program: { select: { name: true, year: true } },
               },
-              orderBy: { addedAt: 'desc' },
-              take: 1,
             },
             teamMembers: {
               include: {
@@ -602,17 +595,10 @@ export const mentorRouter = router({
       const project = await ctx.prisma.project.findUniqueOrThrow({
         where: { id: input.projectId },
         include: {
-          program: { select: { id: true, name: true, year: true } },
-          roundProjects: {
+          round: {
             include: {
-              round: {
-                include: {
-                  program: { select: { id: true, name: true, year: true } },
-                },
-              },
+              program: { select: { id: true, name: true, year: true } },
             },
-            orderBy: { addedAt: 'desc' },
-            take: 1,
           },
           teamMembers: {
             include: {
@@ -660,7 +646,7 @@ export const mentorRouter = router({
     )
     .query(async ({ ctx, input }) => {
       const where = {
-        ...(input.roundId && { project: { roundProjects: { some: { roundId: input.roundId } } } }),
+        ...(input.roundId && { project: { roundId: input.roundId } }),
         ...(input.mentorId && { mentorId: input.mentorId }),
       }
 
@@ -675,10 +661,7 @@ export const mentorRouter = router({
                 teamName: true,
                 oceanIssue: true,
                 competitionCategory: true,
-                roundProjects: {
-                  select: { status: true },
-                  take: 1,
-                },
+                status: true,
               },
             },
             mentor: {