Refactor global styles and enhance MITM functionality

- Updated global CSS to implement a new brand color palette and improve light/dark theme consistency.
- Enhanced the MitmServerCard component to provide clearer user feedback regarding admin privileges.
- Filtered LLM combos in the CombosPage to ensure only relevant data is displayed.
- Improved APIPageClient layout for better usability and visual consistency.
- Added functionality to save and load DNS tool states in the MITM manager.
- Updated OAuth configuration URLs for Qwen to reflect the new endpoint structure.
- Refined tunnel management logic to improve reliability and user experience.

src/app/(dashboard)/dashboard/combos/page.js

@@ -32,7 +32,8 @@ export default function CombosPage() {
       const providersData = await providersRes.json();
       const settingsData = settingsRes.ok ? await settingsRes.json() : {};
       
-      if (combosRes.ok) setCombos(combosData.combos || []);
+      // Only LLM combos here — webSearch/webFetch combos belong to media-providers/web
+      if (combosRes.ok) setCombos((combosData.combos || []).filter(c => !c.kind));
       if (providersRes.ok) {
         setActiveProviders(providersData.connections || []);
       }