Fix juror drop: remove from jury group + reassign projects

The reassignDroppedJuror flow was missing a key step — after
reshuffling unsubmitted projects to other jurors, the dropped juror
was not removed from the jury group. This meant they could be
re-assigned in future assignment runs. Now deletes the JuryGroupMember
record after reshuffle, logs removal in audit, and updates the
confirmation dialog to reflect the full action.

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

src/server/routers/assignment.ts

@@ -433,6 +433,19 @@ async function reassignDroppedJurorAssignments(params: {
     })
   }
 
+  // Remove the dropped juror from the jury group so they can't be re-assigned
+  // in future assignment runs for this round's competition.
+  let removedFromGroup = false
+  if (round.juryGroupId) {
+    const deleted = await prisma.juryGroupMember.deleteMany({
+      where: {
+        juryGroupId: round.juryGroupId,
+        userId: params.droppedJurorId,
+      },
+    })
+    removedFromGroup = deleted.count > 0
+  }
+
   if (params.auditUserId) {
     await logAudit({
       prisma,
@@ -448,6 +461,7 @@ async function reassignDroppedJurorAssignments(params: {
         failedProjects,
         skippedProjects,
         reassignedTo,
+        removedFromGroup,
       },
       ipAddress: params.auditIp,
       userAgent: params.auditUserAgent,