fix: Persist loaded model and mode on ACP session load (#9829)

packages/opencode/src/acp/agent.ts

@@ -513,8 +513,13 @@ export namespace ACP {
         const lastUser = messages?.findLast((m) => m.info.role === "user")?.info
         if (lastUser?.role === "user") {
           result.models.currentModelId = `${lastUser.model.providerID}/${lastUser.model.modelID}`
+          this.sessionManager.setModel(sessionId, {
+            providerID: lastUser.model.providerID,
+            modelID: lastUser.model.modelID,
+          })
           if (result.modes.availableModes.some((m) => m.id === lastUser.agent)) {
             result.modes.currentModeId = lastUser.agent
+            this.sessionManager.setMode(sessionId, lastUser.agent)
           }
         }