fix: unify dialog layout and fix content padding issues

- Fix negative margin overflow in all dialog content areas
- Standardize dialog structure with flex-col layout
- Add consistent py-4 spacing to all content areas
- Ensure proper spacing between header, content, and footer

Affected components:
- AddProviderDialog, EditProviderDialog
- McpFormModal, McpPanel
- UsageScriptModal
- SettingsDialog

All dialogs now follow unified layout pattern:
- DialogContent: flex flex-col max-h-[90vh]
- Content area: flex-1 overflow-y-auto px-6 py-4
- No negative margins that cause content overflow

src/lib/query/queries.ts

@@ -1,4 +1,8 @@
-import { useQuery, type UseQueryResult, keepPreviousData } from "@tanstack/react-query";
+import {
+  useQuery,
+  type UseQueryResult,
+  keepPreviousData,
+} from "@tanstack/react-query";
 import { providersApi, settingsApi, usageApi, type AppType } from "@/lib/api";
 import type { Provider, Settings, UsageResult } from "@/types";