fix(auth): deterministic fallback profile selection when default key missing

For models without explicit authProfile:
- use bare provider key when present
- use :default when present
- otherwise choose first available provider profile (sorted)

Also reflect inferred profile in TUI status when model has no explicit profile.

packages/opencode/src/cli/cmd/tui/context/local.tsx

@@ -1,5 +1,5 @@
 import { createStore } from "solid-js/store"
-import { batch, createEffect, createMemo } from "solid-js"
+import { batch, createEffect, createMemo, createResource } from "solid-js"
 import { useSync } from "@tui/context/sync"
 import { useTheme } from "@tui/context/theme"
 import { uniqueBy } from "remeda"
@@ -9,6 +9,7 @@ import { iife } from "@/util/iife"
 import { createSimpleContext } from "./helper"
 import { useToast } from "../ui/toast"
 import { Provider } from "@/provider/provider"
+import { Auth } from "@/auth"
 import { useArgs } from "./args"
 import { useSDK } from "./sdk"
 import { RGBA } from "@opentui/core"
@@ -208,6 +209,20 @@ export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
           ) ?? undefined
         )
       })
+      const [auths] = createResource(async () => Auth.all())
+
+      const inferredProfile = (providerID: string) => {
+        const data = auths()
+        if (!data) return undefined
+        if (providerID in data) return undefined
+        if (`${providerID}:default` in data) return "default"
+        const prefix = `${providerID}:`
+        const profiles = Object.keys(data)
+          .filter((key) => key.startsWith(prefix))
+          .map((key) => key.slice(prefix.length))
+          .sort()
+        return profiles[0]
+      }
 
       return {
         current: currentModel,
@@ -232,10 +247,11 @@ export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
           }
           const provider = sync.data.provider.find((x) => x.id === value.providerID)
           const info = provider?.models[value.modelID]
+          const profile = value.authProfile ?? inferredProfile(value.providerID)
           return {
             provider: provider?.name ?? value.providerID,
             model: info?.name ?? value.modelID,
-            profile: value.authProfile,
+            profile,
             reasoning: info?.capabilities?.reasoning ?? false,
           }
         }),

packages/opencode/src/session/llm.ts

@@ -90,16 +90,29 @@ export namespace LLM {
       modelID: input.model.id,
       providerID: input.model.providerID,
     })
-    const authKey = input.model.authProfile
-      ? `${input.model.providerID}:${input.model.authProfile}`
-      : input.model.providerID
-    const [cfg, provider, auth] = await Promise.all([
+    const [cfg, provider, auths] = await Promise.all([
       Config.get(),
       Provider.getProvider(input.model.providerID),
-      Auth.get(authKey),
+      Auth.all(),
     ])
+    const chooseProfile = () => {
+      if (input.model.authProfile) return input.model.authProfile
+      if (input.model.providerID in auths) return undefined
+      if (`${input.model.providerID}:default` in auths) return "default"
+      const prefix = `${input.model.providerID}:`
+      const profiles = Object.keys(auths)
+        .filter((key) => key.startsWith(prefix))
+        .map((key) => key.slice(prefix.length))
+        .sort()
+      if (profiles.length === 0) return undefined
+      return profiles[0]
+    }
+    const profile = chooseProfile()
+    const authKey = profile ? `${input.model.providerID}:${profile}` : input.model.providerID
+    const auth = auths[authKey]
     const runtimeModel = {
       ...input.model,
+      ...(profile ? { authProfile: profile } : {}),
       options:
         auth?.type === "api"
           ? mergeDeep(input.model.options, { apiKey: auth.key })