feat: add /model command for changing models inside TUI/CLI (#162)

* rebase main

* fix: apply pr comments

* fix: fix critical issue

* fix: ordering /model in cli mode

* feat: refactor /model command handling and add Rich CLI support

---------

Co-authored-by: X-iZhang <zacharyzhang2022@gmail.com>

tests/test_rich_command_ui.py

@@ -0,0 +1,174 @@
+"""Tests for the Rich CLI CommandUI adapter."""
+
+from unittest.mock import MagicMock
+
+import pytest
+from rich.console import Console
+from rich.table import Table
+
+from tests.conftest import run_async as _run
+
+
+def _make_ui():
+    """Build a RichCLICommandUI backed by a MagicMock console."""
+    from EvoScientist.cli.rich_command_ui import RichCLICommandUI
+
+    console = MagicMock(spec=Console)
+    ui = RichCLICommandUI(console)
+    return ui, console
+
+
+class TestBasicIO:
+    """Core CommandUI methods used by /model path."""
+
+    def test_supports_interactive_true(self):
+        ui, _ = _make_ui()
+        assert ui.supports_interactive is True
+
+    def test_append_system_forwards_style(self):
+        ui, console = _make_ui()
+        ui.append_system("hello", style="green")
+        console.print.assert_called_once_with("hello", style="green")
+
+    def test_append_system_default_style(self):
+        ui, console = _make_ui()
+        ui.append_system("info")
+        console.print.assert_called_once_with("info", style="dim")
+
+    def test_mount_renderable_preserves_type(self):
+        ui, console = _make_ui()
+        table = Table(title="demo")
+        ui.mount_renderable(table)
+        console.print.assert_called_once_with(table)
+
+    def test_flush_is_async_noop(self):
+        ui, console = _make_ui()
+        _run(ui.flush())
+        # flush should not print anything
+        console.print.assert_not_called()
+
+
+class TestWaitForModelPick:
+    """CLI model picker fallback: print table + return None."""
+
+    def test_returns_none(self):
+        ui, _ = _make_ui()
+        entries = [
+            ("claude-sonnet-4-6", "anthropic/claude-sonnet", "anthropic"),
+            ("gpt-4o", "openai/gpt-4o", "openai"),
+        ]
+        result = _run(
+            ui.wait_for_model_pick(
+                entries,
+                current_model="claude-sonnet-4-6",
+                current_provider="anthropic",
+            )
+        )
+        assert result is None
+
+    def test_prints_table_with_current_model_marker(self):
+        ui, console = _make_ui()
+        entries = [
+            ("claude-sonnet-4-6", "anthropic/claude-sonnet", "anthropic"),
+            ("gpt-4o", "openai/gpt-4o", "openai"),
+        ]
+        _run(
+            ui.wait_for_model_pick(
+                entries,
+                current_model="claude-sonnet-4-6",
+                current_provider="anthropic",
+            )
+        )
+        # First call renders the Table (Rich renderable), second prints usage.
+        assert console.print.call_count == 2
+        first_arg = console.print.call_args_list[0].args[0]
+        assert isinstance(first_arg, Table)
+
+        usage_arg = console.print.call_args_list[1].args[0]
+        assert "Usage: /model" in usage_arg
+        assert "--save" in usage_arg
+
+    def test_no_current_model_no_marker(self):
+        ui, console = _make_ui()
+        entries = [("claude-sonnet-4-6", "anthropic/claude-sonnet", "anthropic")]
+        _run(
+            ui.wait_for_model_pick(
+                entries,
+                current_model=None,
+                current_provider=None,
+            )
+        )
+        # Just asserts the coroutine runs without marker-branch issues.
+        assert console.print.call_count == 2
+
+    def test_empty_entries_still_prints_header_and_usage(self):
+        ui, console = _make_ui()
+        result = _run(
+            ui.wait_for_model_pick(
+                [],
+                current_model=None,
+                current_provider=None,
+            )
+        )
+        assert result is None
+        # Header table + usage hint should still be printed even with
+        # no entries.
+        assert console.print.call_count == 2
+
+
+class TestUpdateStatusHook:
+    """update_status_after_model_change is a deliberate no-op on CLI."""
+
+    def test_no_op(self):
+        ui, console = _make_ui()
+        ui.update_status_after_model_change("claude-opus-4-6", "anthropic")
+        console.print.assert_not_called()
+
+
+class TestUnmigratedMethodsStub:
+    """Protocol methods not yet wired for CLI must raise NotImplementedError.
+
+    These stubs are signposts for the A1 migration (see
+    cli-commandmanager-migration.md). Each one is replaced by a real
+    implementation when its corresponding command is migrated.
+    """
+
+    def test_wait_for_thread_pick(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/threads"):
+            _run(ui.wait_for_thread_pick([], "tid", "title"))
+
+    def test_wait_for_skill_browse(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/skills"):
+            _run(ui.wait_for_skill_browse([], set(), ""))
+
+    def test_wait_for_mcp_browse(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/mcp"):
+            _run(ui.wait_for_mcp_browse([], set(), ""))
+
+    def test_clear_chat(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/clear"):
+            ui.clear_chat()
+
+    def test_request_quit(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/exit"):
+            ui.request_quit()
+
+    def test_force_quit(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/exit"):
+            ui.force_quit()
+
+    def test_start_new_session(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/new"):
+            ui.start_new_session()
+
+    def test_handle_session_resume(self):
+        ui, _ = _make_ui()
+        with pytest.raises(NotImplementedError, match="/resume"):
+            _run(ui.handle_session_resume("tid"))