Add per-juror notify button in Jury Progress section

Adds a mail icon on hover for each juror row in the Jury Progress
table, allowing admins to send assignment notifications to individual
jurors instead of only bulk-notifying all at once.

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

src/app/(admin)/admin/rounds/[roundId]/page.tsx

@@ -2363,11 +2363,18 @@ function JuryProgressTable({ roundId }: { roundId: string }) {
     { refetchInterval: 15_000 },
   )
 
+  const notifyMutation = trpc.assignment.notifySingleJurorOfAssignments.useMutation({
+    onSuccess: (data) => {
+      toast.success(`Notified juror of ${data.projectCount} assignment(s)`)
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
   return (
     <Card>
       <CardHeader>
         <CardTitle className="text-base">Jury Progress</CardTitle>
-        <CardDescription>Evaluation completion per juror</CardDescription>
+        <CardDescription>Evaluation completion per juror. Click the mail icon to notify an individual juror.</CardDescription>
       </CardHeader>
       <CardContent>
         {isLoading ? (
@@ -2391,12 +2398,34 @@ function JuryProgressTable({ roundId }: { roundId: string }) {
                     : 'bg-gray-300'
 
               return (
-                <div key={juror.id} className="space-y-1 hover:bg-muted/20 rounded px-1 py-0.5 -mx-1 transition-colors">
-                  <div className="flex justify-between text-xs">
-                    <span className="font-medium truncate max-w-[60%]">{juror.name}</span>
-                    <span className="text-muted-foreground shrink-0 tabular-nums">
-                      {juror.completed}/{juror.assigned} ({pct}%)
-                    </span>
+                <div key={juror.id} className="space-y-1 hover:bg-muted/20 rounded px-1 py-0.5 -mx-1 transition-colors group">
+                  <div className="flex justify-between items-center text-xs">
+                    <span className="font-medium truncate max-w-[50%]">{juror.name}</span>
+                    <div className="flex items-center gap-2 shrink-0">
+                      <span className="text-muted-foreground tabular-nums">
+                        {juror.completed}/{juror.assigned} ({pct}%)
+                      </span>
+                      <TooltipProvider delayDuration={200}>
+                        <Tooltip>
+                          <TooltipTrigger asChild>
+                            <Button
+                              variant="ghost"
+                              size="icon"
+                              className="h-5 w-5 opacity-0 group-hover:opacity-100 transition-opacity"
+                              disabled={notifyMutation.isPending}
+                              onClick={() => notifyMutation.mutate({ roundId, userId: juror.id })}
+                            >
+                              {notifyMutation.isPending && notifyMutation.variables?.userId === juror.id ? (
+                                <Loader2 className="h-3 w-3 animate-spin" />
+                              ) : (
+                                <Mail className="h-3 w-3" />
+                              )}
+                            </Button>
+                          </TooltipTrigger>
+                          <TooltipContent side="left"><p>Notify this juror of their assignments</p></TooltipContent>
+                        </Tooltip>
+                      </TooltipProvider>
+                    </div>
                   </div>
                   <div className="h-2 bg-muted rounded-full overflow-hidden">
                     <div