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/hooks/useMcpActions.ts

@@ -66,10 +66,9 @@ export function useMcpActions(appType: AppType): UseMcpActionsResult {
 
       try {
         await mcpApi.setEnabled(appType, id, enabled);
-        toast.success(
-          enabled ? t("mcp.msg.enabled") : t("mcp.msg.disabled"),
-          { duration: 1500 },
-        );
+        toast.success(enabled ? t("mcp.msg.enabled") : t("mcp.msg.disabled"), {
+          duration: 1500,
+        });
       } catch (error) {
         // Rollback on failure
         setServers(previousServers);