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>

vite.config.js

@@ -1,6 +1,5 @@
 import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
-import { sentryVitePlugin } from '@sentry/vite-plugin';
 import { wasm } from '@rollup/plugin-wasm';
 import inject from '@rollup/plugin-inject';
 import { viteStaticCopy } from 'vite-plugin-static-copy';
@@ -261,20 +260,6 @@ export default defineConfig({
     react(),
     copyPdfWorker(),
     lotusDenoise(),
-    ...(process.env.SENTRY_AUTH_TOKEN
-      ? [
-          sentryVitePlugin({
-            org: 'lotus-guild',
-            project: 'javascript-react',
-            authToken: process.env.SENTRY_AUTH_TOKEN,
-            sourcemaps: {
-              filesToDeleteAfterUpload: ['./dist/**/*.map'],
-            },
-            release: { name: process.env.VITE_APP_VERSION ?? 'lotus' },
-            telemetry: false,
-          }),
-        ]
-      : []),
     VitePWA({
       srcDir: 'src',
       filename: 'sw.ts',
@@ -302,7 +287,7 @@ export default defineConfig({
   build: {
     target: 'esnext',
     outDir: 'dist',
-    sourcemap: process.env.SENTRY_AUTH_TOKEN ? 'hidden' : false,
+    sourcemap: false,
     copyPublicDir: false,
     // manualChunks must be in rolldownOptions (not rollupOptions) for Vite 8 / Rolldown
     rolldownOptions: {