fix: handle both string and object formats in providers array

- Support providers as array of strings: [opencode, chutes]
- Support providers as array of objects: [{provider: opencode}]
- This fixes provider detection for Chutes and other providers

chat/server.js

@@ -5134,10 +5134,10 @@ async function ensureOpencodeConfig(session) {
   log('ensureOpencodeConfig debug', {
     sessionId: session.id,
     adminModelsCount: adminModels.length,
-    adminModelsSample: adminModels.slice(0, 2).map(m => ({ 
+    adminModelsSample: adminModels.slice(0, 3).map(m => ({ 
       id: m.id, 
       name: m.name, 
-      providers: m.providers?.map(p => p.provider),
+      providers: m.providers,
       primaryProvider: m.primaryProvider 
     })),
     chutesKeyExists: !!CHUTES_API_KEY,
@@ -5149,7 +5149,12 @@ async function ensureOpencodeConfig(session) {
   for (const model of adminModels) {
     if (Array.isArray(model.providers)) {
       for (const p of model.providers) {
-        if (p.provider) usedProviders.add(p.provider.toLowerCase());
+        // Handle both string format ["opencode", "chutes"] and object format [{provider: "opencode"}]
+        if (typeof p === 'string') {
+          usedProviders.add(p.toLowerCase());
+        } else if (p && typeof p === 'object' && p.provider) {
+          usedProviders.add(p.provider.toLowerCase());
+        }
       }
     }
     if (model.primaryProvider) {