Polish: homework filters, users search/popup, admin comments

Homework (/curator/homework):
- Search by student name/email
- Filter by status (pending/reviewed) and course
- Server-side pagination (20 per page) with URL params

Users (/admin/users):
- Search by name/email, filter by role
- Hover popup on each row: enrolled courses + expiry dates + email
- Pagination (20 per page) with URL params

Comments (/admin/comments):
- New admin page with all active comments
- Search by author or text content
- One-click delete (soft-delete) from the table
- Pagination (30 per page)
- Added "Комментарии" link to admin nav

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

src/components/admin/users-search.tsx

@@ -0,0 +1,70 @@
+"use client";
+
+import { useRouter, usePathname } from "next/navigation";
+import { useTransition } from "react";
+import { Search } from "lucide-react";
+
+const inputStyle: React.CSSProperties = {
+  border: "2px solid var(--border)",
+  background: "var(--background)",
+  outline: "none",
+  padding: "0.4rem 0.75rem",
+  fontSize: "0.8rem",
+  fontFamily: "inherit",
+};
+
+export function UsersSearch({ initialSearch, initialRole }: { initialSearch: string; initialRole: string }) {
+  const router = useRouter();
+  const pathname = usePathname();
+  const [, startTransition] = useTransition();
+
+  function update(search: string, role: string) {
+    const params = new URLSearchParams();
+    if (search) params.set("search", search);
+    if (role) params.set("role", role);
+    startTransition(() => router.push(`${pathname}?${params.toString()}`));
+  }
+
+  return (
+    <div className="flex flex-wrap gap-2 mb-4">
+      <div className="relative">
+        <Search size={13} className="absolute left-2.5 top-1/2 -translate-y-1/2" style={{ color: "var(--muted-foreground)" }} />
+        <input
+          defaultValue={initialSearch}
+          placeholder="Поиск по имени или email"
+          style={{ ...inputStyle, paddingLeft: "2rem", width: 240 }}
+          onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
+          onBlur={(e) => {
+            e.currentTarget.style.borderColor = "var(--border)";
+            update(e.currentTarget.value.trim(), initialRole);
+          }}
+          onKeyDown={(e) => { if (e.key === "Enter") e.currentTarget.blur(); }}
+        />
+      </div>
+
+      <select
+        defaultValue={initialRole}
+        onChange={(e) => update(initialSearch, e.target.value)}
+        style={{ ...inputStyle, appearance: "none", cursor: "pointer" }}
+        onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
+        onBlur={(e) => (e.currentTarget.style.borderColor = "var(--border)")}
+      >
+        <option value="">Все роли</option>
+        <option value="student">Ученики</option>
+        <option value="curator">Кураторы</option>
+        <option value="admin">Администраторы</option>
+      </select>
+
+      {(initialSearch || initialRole) && (
+        <button
+          type="button"
+          onClick={() => startTransition(() => router.push(pathname))}
+          className="text-xs px-3"
+          style={{ border: "2px solid var(--border)", color: "var(--muted-foreground)" }}
+        >
+          Сбросить
+        </button>
+      )}
+    </div>
+  );
+}