add dashboard import/export functionality (#1204)

Adds Dashboard Import/Export UI to support sharing premade dashboards

<img width="286" height="171" alt="Screenshot 2025-09-24 at 10 10 55 AM" src="https://github.com/user-attachments/assets/dbc61cad-a7e6-42c6-85b8-de049beb7d56" />
<img width="1037" height="625" alt="Screenshot 2025-09-24 at 10 10 48 AM" src="https://github.com/user-attachments/assets/4233bdd8-fb73-4c8a-953f-5a59f5e53108" />

Fixes HDX-2463

Author: brandon-pereira

.changeset/smooth-ladybugs-care.md

@@ -0,0 +1,6 @@
+---
+"@hyperdx/common-utils": patch
+"@hyperdx/app": patch
+---
+
+add dashboard import/export functionality

packages/app/.storybook/preview.tsx

@@ -8,6 +8,7 @@ import { NextAdapter } from 'next-query-params';
 import '@mantine/core/styles.css';
 import '@mantine/notifications/styles.css';
 import '@mantine/dates/styles.css';
+import '@mantine/dropzone/styles.css';
 
 import '../styles/globals.css';
 import '../styles/app.scss';

packages/app/package.json

@@ -34,6 +34,7 @@
     "@lezer/highlight": "^1.2.0",
     "@mantine/core": "7.9.2",
     "@mantine/dates": "^7.11.2",
+    "@mantine/dropzone": "^8.3.1",
     "@mantine/form": "^7.11.2",
     "@mantine/hooks": "7.9.2",
     "@mantine/notifications": "^7.9.2",

packages/app/pages/_app.tsx

@@ -26,6 +26,7 @@ import { useBackground, useUserPreferences } from '@/useUserPreferences';
 import '@mantine/core/styles.css';
 import '@mantine/notifications/styles.css';
 import '@mantine/dates/styles.css';
+import '@mantine/dropzone/styles.css';
 import '@styles/globals.css';
 import '@styles/app.scss';
 import 'uplot/dist/uPlot.min.css';

packages/app/pages/dashboards/import.tsx

@@ -0,0 +1,3 @@
+import DBDashboardImportPage from '@/DBDashboardImportPage';
+
+export default DBDashboardImportPage;