chore: remove Sentry.io entirely

We no longer use Sentry. Removed:
- @sentry/react + @sentry/vite-plugin (package.json + lockfile)
- Sentry.init in index.tsx and the VITE_SENTRY_DSN env (.env.production)
- @sentry/vite-plugin + the SENTRY_AUTH_TOKEN sourcemap-upload path in
  vite.config.js (sourcemap now always false) and the CI env var
- Sentry.ErrorBoundary in App.tsx -> react-error-boundary's ErrorBoundary with a
  folds-native fallback (Box/Text/Button + config tokens), which also resolves
  the native-cinny audit's raw-#hex/#5865f2 fallback finding.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/pages/App.tsx

@@ -1,7 +1,16 @@
 import React, { useEffect } from 'react';
-import * as Sentry from '@sentry/react';
+import { ErrorBoundary } from 'react-error-boundary';
 import { Provider as JotaiProvider, useAtomValue } from 'jotai';
-import { OverlayContainerProvider, PopOutContainerProvider, TooltipContainerProvider } from 'folds';
+import {
+  Box,
+  Button,
+  config,
+  OverlayContainerProvider,
+  PopOutContainerProvider,
+  Text,
+  toRem,
+  TooltipContainerProvider,
+} from 'folds';
 import { RouterProvider } from 'react-router-dom';
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 import { ReactQueryDevtools } from '@tanstack/react-query-devtools';
@@ -102,41 +111,25 @@ function App() {
   const portalContainer = document.getElementById('portalContainer') ?? undefined;
 
   return (
-    <Sentry.ErrorBoundary
-      fallback={({ error, resetError }) => (
-        <div
-          style={{
-            display: 'flex',
-            flexDirection: 'column',
-            alignItems: 'center',
-            justifyContent: 'center',
-            height: '100vh',
-            gap: '16px',
-            fontFamily: 'sans-serif',
-            padding: '24px',
-            textAlign: 'center',
-          }}
+    <ErrorBoundary
+      fallbackRender={({ error, resetErrorBoundary }) => (
+        <Box
+          direction="Column"
+          alignItems="Center"
+          justifyContent="Center"
+          gap="400"
+          style={{ height: '100vh', padding: config.space.S700, textAlign: 'center' }}
         >
-          <h2 style={{ margin: 0 }}>Something went wrong</h2>
-          <p style={{ margin: 0, color: '#666', maxWidth: '400px' }}>
+          <Text size="H2">Something went wrong</Text>
+          <Text size="T300" priority="300" style={{ maxWidth: toRem(400) }}>
             {error instanceof Error ? error.message : 'An unexpected error occurred.'}
-          </p>
-          <button
-            type="button"
-            onClick={resetError}
-            style={{
-              padding: '8px 20px',
-              borderRadius: '6px',
-              border: 'none',
-              background: '#5865f2',
-              color: '#fff',
-              cursor: 'pointer',
-              fontSize: '14px',
-            }}
-          >
-            Try again
-          </button>
-        </div>
+          </Text>
+          <Button variant="Primary" onClick={resetErrorBoundary}>
+            <Text as="span" size="B400">
+              Try again
+            </Text>
+          </Button>
+        </Box>
       )}
     >
       <TooltipContainerProvider value={portalContainer}>
@@ -171,7 +164,7 @@ function App() {
           </OverlayContainerProvider>
         </PopOutContainerProvider>
       </TooltipContainerProvider>
-    </Sentry.ErrorBoundary>
+    </ErrorBoundary>
   );
 }
 

src/index.tsx

@@ -1,5 +1,4 @@
 /* eslint-disable import/first */
-import * as Sentry from '@sentry/react';
 import React from 'react';
 import { createRoot } from 'react-dom/client';
 import { enableMapSet } from 'immer';
@@ -7,31 +6,6 @@ import '@fontsource-variable/inter/index.css';
 import 'folds/dist/style.css';
 import { configClass, varsClass } from 'folds';
 
-const sentryDsn = import.meta.env.VITE_SENTRY_DSN;
-if (sentryDsn) {
-  Sentry.init({
-    dsn: sentryDsn,
-    environment: import.meta.env.MODE,
-    release: import.meta.env.VITE_APP_VERSION,
-    // browserTracingIntegration omitted — it injects sentry-trace/baggage headers
-    // into outgoing fetch calls, which breaks Synapse CORS on matrix.lotusguild.org
-    // No propagation targets — we don't control the Matrix server's CORS allow-list
-    tracePropagationTargets: [],
-    tracesSampleRate: 0,
-    // Don't send PII (IPs, usernames) — this is a private chat app
-    sendDefaultPii: false,
-    // Forward Sentry logs to the dashboard
-    enableLogs: true,
-    // Suppress benign PostmessageTransport / matrixRTC heartbeat timeouts (upstream library noise)
-    ignoreErrors: ['Request timed out'],
-    beforeSend(event) {
-      // Drop any event that may have leaked an access token into breadcrumbs/data
-      if (JSON.stringify(event).includes('access_token')) return null;
-      return event;
-    },
-  });
-}
-
 enableMapSet();
 
 import './index.css';