fix(frontend): Fix lint and type errors in waitlist admin components

- Remove unused WaitlistSignup import
- Change button size from "sm" to "small"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

autogpt_platform/frontend/src/app/(platform)/admin/waitlist/components/WaitlistSignupsDialog.tsx

@@ -19,7 +19,6 @@ import {
 } from "@/components/__legacy__/ui/table";
 import {
   getWaitlistSignups,
-  type WaitlistSignup,
   type WaitlistSignupListResponse,
 } from "../actions";
 import { useToast } from "@/components/molecules/Toast/use-toast";

autogpt_platform/frontend/src/app/(platform)/admin/waitlist/components/WaitlistTable.tsx

@@ -149,7 +149,7 @@ export function WaitlistTable() {
                   <div className="flex gap-2">
                     <Button
                       variant="ghost"
-                      size="sm"
+                      size="small"
                       onClick={() => setViewingSignups(waitlist.id)}
                       title="View signups"
                     >
@@ -157,7 +157,7 @@ export function WaitlistTable() {
                     </Button>
                     <Button
                       variant="ghost"
-                      size="sm"
+                      size="small"
                       onClick={() => setEditingWaitlist(waitlist)}
                       title="Edit"
                     >
@@ -165,7 +165,7 @@ export function WaitlistTable() {
                     </Button>
                     <Button
                       variant="ghost"
-                      size="sm"
+                      size="small"
                       onClick={() => handleDelete(waitlist.id)}
                       title="Delete"
                     >