Decouple projects from rounds with RoundProject join table

Projects now exist at the program level instead of being locked to a
single round. A new RoundProject join table enables many-to-many
relationships with per-round status tracking. Rounds have sortOrder
for configurable progression paths.

- Add RoundProject model, programId on Project, sortOrder on Round
- Migration preserves existing data (roundId -> RoundProject entries)
- Update all routers to query through RoundProject join
- Add assign/remove/advance/reorder round endpoints
- Add Assign, Advance, Remove Projects dialogs on round detail page
- Add round reorder controls (up/down arrows) on rounds list
- Show all rounds on project detail page

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

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

@@ -139,20 +139,29 @@ function ProjectDetailContent({ projectId }: { projectId: string }) {
             fallback="initials"
           />
           <div className="space-y-1">
-            <div className="flex items-center gap-2 text-sm text-muted-foreground">
-              <Link
-                href={`/admin/rounds/${project.round.id}`}
-                className="hover:underline"
-              >
-                {project.round.name}
-              </Link>
+            <div className="flex flex-wrap items-center gap-1 text-sm text-muted-foreground">
+              {project.roundProjects?.length > 0 ? (
+                project.roundProjects.map((rp, i) => (
+                  <span key={rp.round.id} className="flex items-center gap-1">
+                    {i > 0 && <span className="text-muted-foreground/50">/</span>}
+                    <Link
+                      href={`/admin/rounds/${rp.round.id}`}
+                      className="hover:underline"
+                    >
+                      {rp.round.name}
+                    </Link>
+                  </span>
+                ))
+              ) : (
+                <span>No round</span>
+              )}
             </div>
             <div className="flex items-center gap-3">
               <h1 className="text-2xl font-semibold tracking-tight">
                 {project.title}
               </h1>
-              <Badge variant={statusColors[project.status] || 'secondary'}>
-                {project.status.replace('_', ' ')}
+              <Badge variant={statusColors[project.roundProjects?.[0]?.status ?? 'SUBMITTED'] || 'secondary'}>
+                {(project.roundProjects?.[0]?.status ?? 'SUBMITTED').replace('_', ' ')}
               </Badge>
             </div>
             {project.teamName && (
@@ -504,7 +513,7 @@ function ProjectDetailContent({ projectId }: { projectId: string }) {
                 </CardDescription>
               </div>
               <Button variant="outline" size="sm" asChild>
-                <Link href={`/admin/rounds/${project.roundId}/assignments`}>
+                <Link href={`/admin/rounds/${project.roundProjects?.[0]?.round?.id}/assignments`}>
                   Manage
                 </Link>
               </Button>