feat(ui): add model support for custom providers and improve UX

- Support custom provider models in combos and model selection
- Display custom provider names instead of technical IDs
- Make model fields readonly (selected via modal)
- Only show connected providers (remove fallback)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/(dashboard)/dashboard/cli-tools/CLIToolsPageClient.js

@@ -88,22 +88,6 @@ export default function CLIToolsPageClient({ machineId }) {
       });
     });
     
-    if (models.length === 0) {
-      Object.entries(PROVIDER_MODELS).forEach(([alias, providerModels]) => {
-        providerModels.forEach(m => {
-          const modelValue = `${alias}/${m.id}`;
-          models.push({
-            value: modelValue,
-            label: `${alias}/${m.id}`,
-            provider: alias,
-            alias: alias,
-            connectionName: alias,
-            modelId: m.id,
-          });
-        });
-      });
-    }
-    
     return models;
   };