fix: repair stale defaultProviderId in storage on load

When the stored default provider ID doesn't match any loaded provider,
write back the corrected ID (providers[0].id) to storage so it doesn't
silently persist across sessions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/browseros-agent/apps/agent/entrypoints/sidepanel/index/useChatSession.ts

@@ -23,6 +23,7 @@ import {
 import { formatConversationHistory } from '@/lib/conversations/formatConversationHistory'
 import { declinedAppsStorage } from '@/lib/declined-apps/storage'
 import { useGraphqlQuery } from '@/lib/graphql/useGraphqlQuery'
+import { createDefaultBrowserOSProvider } from '@/lib/llm-providers/storage'
 import { useLlmProviders } from '@/lib/llm-providers/useLlmProviders'
 import { track } from '@/lib/metrics/track'
 import { searchActionsStorage } from '@/lib/search-actions/searchActionsStorage'
@@ -208,7 +209,7 @@ export const useChatSession = (options?: ChatSessionOptions) => {
         })
         const activeTab = activeTabsList?.[0] ?? undefined
         const message = getLastMessageText(messages)
-        const provider = selectedLlmProviderRef.current
+        const provider = selectedLlmProviderRef.current ?? createDefaultBrowserOSProvider()
         const currentMode = modeRef.current
         const enabledMcpServers = enabledMcpServersRef.current
         const customMcpServers = enabledCustomServersRef.current

packages/browseros-agent/apps/agent/lib/llm-providers/useLlmProviders.ts

@@ -60,6 +60,15 @@ export function useLlmProviders(): UseLlmProvidersReturn {
           await defaultProviderIdStorage.setValue(loadedDefaultId)
         }
 
+        // Repair stale default ID that doesn't match any provider
+        const defaultExists = loadedProviders.some(
+          (p) => p.id === loadedDefaultId,
+        )
+        if (!defaultExists && loadedProviders.length > 0) {
+          loadedDefaultId = loadedProviders[0].id
+          await defaultProviderIdStorage.setValue(loadedDefaultId)
+        }
+
         setProviders(loadedProviders)
         setDefaultProviderId(loadedDefaultId)
       } catch {
@@ -146,8 +155,12 @@ export function useLlmProviders(): UseLlmProvidersReturn {
     await providersStorage.setValue(updatedProviders)
   }
 
+  // Fall back to first provider if defaultProviderId is stale/invalid
   const selectedProvider = useMemo(
-    () => providers.find((p) => p.id === defaultProviderId) ?? null,
+    () =>
+      providers.find((p) => p.id === defaultProviderId) ??
+      providers[0] ??
+      null,
     [providers, defaultProviderId],
   )
 

packages/browseros-agent/apps/agent/lib/schedules/getChatServerResponse.ts

@@ -2,6 +2,7 @@ import { createParser, type EventSourceMessage } from 'eventsource-parser'
 import type { ChatMode } from '@/entrypoints/sidepanel/index/chatTypes'
 import { getAgentServerUrl } from '@/lib/browseros/helpers'
 import {
+  createDefaultBrowserOSProvider,
   defaultProviderIdStorage,
   providersStorage,
 } from '@/lib/llm-providers/storage'
@@ -78,7 +79,7 @@ export async function getChatServerResponse(
   request: ChatServerRequest,
 ): Promise<ChatServerResponse> {
   const agentServerUrl = await getAgentServerUrl()
-  const provider = await getDefaultProvider()
+  const provider = (await getDefaultProvider()) ?? createDefaultBrowserOSProvider()
   const conversationId = request.conversationId ?? crypto.randomUUID()
   const personalization = await personalizationStorage.getValue()