fix: revert giphy 10.x (styled-components API break), clean WelcomePage

@giphy/react-components@10.x calls styled-components internals
(mergeAttributes) that do not exist in styled-components v6 — crashes
on open. Reverted to 1.6.0 until giphy publishes a v6-compatible release.

WelcomePage: remove Sentry test button (verified working), rename
Support -> Lotus Matrix Guide.

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

package.json

@@ -68,8 +68,8 @@
     "@atlaskit/pragmatic-drag-and-drop-hitbox": "1.1.0",
     "@fontsource/inter": "4.5.14",
     "@giphy/js-fetch-api": "5.8.0",
-    "@giphy/js-types": "5.1.0",
-    "@giphy/react-components": "10.1.2",
+    "@giphy/js-types": "4.3.0",
+    "@giphy/react-components": "1.6.0",
     "@sentry/react": "10.53.1",
     "@tanstack/react-query": "5.100.11",
     "@tanstack/react-query-devtools": "5.100.11",

src/app/pages/client/WelcomePage.tsx

@@ -1,5 +1,4 @@
 import React from 'react';
-import * as Sentry from '@sentry/react';
 import { Box, Button, Icon, Icons, Text, config, toRem } from 'folds';
 import { Page, PageHero, PageHeroSection } from '../../components/page';
 import LotusLogo from '../../../../public/res/Lotus.png';
@@ -61,18 +60,7 @@ export function WelcomePage() {
                   before={<Icon size="200" src={Icons.Heart} />}
                 >
                   <Text as="span" size="B400" truncate>
-                    Support
-                  </Text>
-                </Button>
-                <Button
-                  onClick={() => {
-                    throw new Error('Sentry test error');
-                  }}
-                  fill="Soft"
-                  before={<Icon size="200" src={Icons.Warning} />}
-                >
-                  <Text as="span" size="B400" truncate>
-                    Test Sentry
+                    Lotus Matrix Guide
                   </Text>
                 </Button>
               </Box>