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/components/providers/forms/CodexConfigEditor.tsx

@@ -60,9 +60,12 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
   const [isCommonConfigModalOpen, setIsCommonConfigModalOpen] = useState(false);
 
   // Use internal state or external state
-  const [internalTemplateModalOpen, setInternalTemplateModalOpen] = useState(false);
-  const isTemplateModalOpen = externalTemplateModalOpen ?? internalTemplateModalOpen;
-  const setIsTemplateModalOpen = externalSetTemplateModalOpen ?? setInternalTemplateModalOpen;
+  const [internalTemplateModalOpen, setInternalTemplateModalOpen] =
+    useState(false);
+  const isTemplateModalOpen =
+    externalTemplateModalOpen ?? internalTemplateModalOpen;
+  const setIsTemplateModalOpen =
+    externalSetTemplateModalOpen ?? setInternalTemplateModalOpen;
 
   // Auto-open common config modal if there's an error
   useEffect(() => {
@@ -74,7 +77,7 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
   const handleQuickWizardApply = (
     auth: string,
     config: string,
-    extras: { websiteUrl?: string; displayName?: string }
+    extras: { websiteUrl?: string; displayName?: string },
   ) => {
     onAuthChange(auth);
     onConfigChange(config);