fix: filter juror preferences banner to review-round groups

The "Confirm Your Evaluation Preferences" banner was including jury
group memberships whose only rounds are LIVE_FINAL or DELIBERATION.
Those ceremonies don't use cap+category preferences, so the sliders
were meaningless. Filter getOnboardingContext to memberships in
groups with at least one INTAKE/FILTERING/EVALUATION/SUBMISSION/
MENTORING round.

Spec: docs/superpowers/specs/2026-04-28-mentor-round-readiness-design.md §E
Plan: docs/superpowers/plans/2026-04-28-pr1-jury-preferences-filter.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/server/routers/user.ts

@@ -1396,7 +1396,18 @@ export const userRouter = router({
    */
   getOnboardingContext: protectedProcedure.query(async ({ ctx }) => {
     const memberships = await ctx.prisma.juryGroupMember.findMany({
-      where: { userId: ctx.user.id },
+      where: {
+        userId: ctx.user.id,
+        juryGroup: {
+          rounds: {
+            some: {
+              roundType: {
+                in: ['INTAKE', 'FILTERING', 'EVALUATION', 'SUBMISSION', 'MENTORING'],
+              },
+            },
+          },
+        },
+      },
       include: {
         juryGroup: {
           select: {