feat: applicant onboarding, bulk invite, team management enhancements

- Add nationality/institution fields to User model with migration
- Applicant onboarding wizard (name, photo, nationality, country, institution, bio, project logo, preferences)
- Project logo upload from applicant context with team membership verification
- APPLICANT redirects in set-password, onboarding, and auth layout
- Mask evaluation round names as "Evaluation Round 1/2/..." for applicants
- Extend inviteTeamMember with nationality/country/institution/sendInvite fields
- Admin getApplicants query with search/filter/pagination
- Admin bulkInviteApplicants mutation with token generation and emails
- Applicants tab on Members page with bulk select and floating invite bar

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

prisma/schema.prisma

@@ -308,6 +308,8 @@ model User {
   expertiseTags  String[]   @default([])
   maxAssignments Int? // Per-round limit
   country        String? // User's home country (for mentor matching)
+  nationality    String? // User's nationality (for applicant profiles)
+  institution    String? // User's institution/organization
   metadataJson   Json?      @db.JsonB
 
   // Profile