ACP loadSessionMode doesn't restore persisted model/agent from session messages

[noamzbr]

Description

When loading an existing session via ACP, loadSessionMode() always uses defaultModel() instead of reading the model/agent from the last user message like the TUI does (prompt/index.tsx:145-148).

This causes the model/mode selection to reset to defaults when reloading a session through ACP clients.

Plugins

No response

OpenCode version

1.1.6

Steps to reproduce

No response

Screenshot and/or share link

No response

Operating System

macOS 15.6.1

Terminal

Ghostty

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Feature Request: Retain current model and agent selection when switching sessions #4930: Retain current model and agent selection when switching sessions (related feature request about session model/agent persistence)
• Selected model for agent in TUI doesn't stick between Agent Alternation #4344: Selected model for agent in TUI doesn't stick between Agent Alternation (related model selection persistence issue)
• opencode --continue doesn't restore state of previous subagent pane #5000: opencode --continue doesn't restore state of previous subagent pane (related to state restoration)

Feel free to ignore if none of these address your specific case.