LLM cleanup (#5462)

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>

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

@@ -348,7 +348,11 @@ export namespace MessageV2 {
     parentID: z.string(),
     modelID: z.string(),
     providerID: z.string(),
+    /**
+     * @deprecated
+     */
     mode: z.string(),
+    agent: z.string(),
     path: z.object({
       cwd: z.string(),
       root: z.string(),
@@ -412,12 +416,7 @@ export namespace MessageV2 {
   })
   export type WithParts = z.infer<typeof WithParts>
 
-  export function toModelMessage(
-    input: {
-      info: Info
-      parts: Part[]
-    }[],
-  ): ModelMessage[] {
+  export function toModelMessage(input: WithParts[]): ModelMessage[] {
     const result: UIMessage[] = []
 
     for (const msg of input) {
@@ -461,6 +460,15 @@ export namespace MessageV2 {
       }
 
       if (msg.info.role === "assistant") {
+        if (
+          msg.info.error &&
+          !(
+            MessageV2.AbortedError.isInstance(msg.info.error) &&
+            msg.parts.some((part) => part.type !== "step-start" && part.type !== "reasoning")
+          )
+        ) {
+          continue
+        }
         const assistantMessage: UIMessage = {
           id: msg.info.id,
           role: "assistant",