fix: propagate authProfile through message chain to Auth.get

- message-v2.ts: add authProfile to User.model schema
- prompt.ts: copy authProfile from model to userMsg.model
- lllm.ts: build auth key with profile when calling Auth.get()
- acp/types.ts: add authProfile to ACPSessionState.model
- acp/agent.ts: propagate authProfile in setModel call

This fixes the bug where embedded profiles (e.g., 'minimax-coding-plan:personal')
were lost when creating user messages and never reached Auth.get().

packages/opencode/src/acp/agent.ts

@@ -659,6 +659,7 @@ export namespace ACP {
           this.sessionManager.setModel(sessionId, {
             providerID: ProviderID.make(lastUser.model.providerID),
             modelID: ModelID.make(lastUser.model.modelID),
+            authProfile: (lastUser.model as { authProfile?: string }).authProfile,
           })
           if (result.modes?.availableModes.some((m) => m.id === lastUser.agent)) {
             result.modes.currentModeId = lastUser.agent

packages/opencode/src/acp/types.ts

@@ -10,6 +10,7 @@ export interface ACPSessionState {
   model?: {
     providerID: ProviderID
     modelID: ModelID
+    authProfile?: string
   }
   variant?: string
   modeId?: string

packages/opencode/src/session/llm.ts

@@ -94,7 +94,9 @@ export namespace LLM {
       Provider.getLanguage(input.model),
       Config.get(),
       Provider.getProvider(input.model.providerID),
-      Auth.get(input.model.providerID),
+      Auth.get(
+        input.model.authProfile ? `${input.model.providerID}:${input.model.authProfile}` : input.model.providerID,
+      ),
     ])
     // TODO: move this to a proper hook
     const isOpenaiOauth = provider.id === "openai" && auth?.type === "oauth"

packages/opencode/src/session/message-v2.ts

@@ -371,6 +371,7 @@ export namespace MessageV2 {
     model: z.object({
       providerID: ProviderID.zod,
       modelID: ModelID.zod,
+      authProfile: z.string().optional(),
     }),
     system: z.string().optional(),
     tools: z.record(z.string(), z.boolean()).optional(),

packages/opencode/src/session/prompt.ts

@@ -761,7 +761,11 @@ NOTE: At any point in time through this workflow you should feel free to ask the
           time: { created: Date.now() },
           role: "user",
           agent: input.agent,
-          model: { providerID: model.providerID, modelID: model.modelID },
+          model: {
+            providerID: model.providerID,
+            modelID: model.modelID,
+            authProfile: (model as { authProfile?: string }).authProfile,
+          },
         }
         yield* sessions.updateMessage(userMsg)
         const userPart: MessageV2.Part = {