feat(agent): make model presets session-scoped (#4866)

tests/webui/test_session_list_index.py

@@ -4,11 +4,14 @@ import os
 from datetime import datetime
 from pathlib import Path
 
+import pytest
+
 import nanobot.webui.session_list_index as session_list_index
 from nanobot.cron.session_turns import CRON_HISTORY_META
 from nanobot.session.automation_turns import AUTOMATION_HISTORY_META
 from nanobot.session.history_visibility import HIDDEN_HISTORY_META
 from nanobot.session.manager import SessionManager
+from nanobot.session.model_selection import SESSION_MODEL_PRESET_METADATA_KEY
 
 
 def test_webui_session_list_reuses_valid_index_without_scanning_files(
@@ -17,10 +20,12 @@ def test_webui_session_list_reuses_valid_index_without_scanning_files(
 ) -> None:
     manager = SessionManager(tmp_path)
     session = manager.get_or_create("websocket:indexed")
+    session.metadata[SESSION_MODEL_PRESET_METADATA_KEY] = "fast"
     session.add_message("user", "indexed preview")
     manager.save(session)
 
     assert list_webui_sessions(manager)[0]["preview"] == "indexed preview"
+    assert list_webui_sessions(manager)[0]["model_preset"] == "fast"
 
     def fail_scan(session_manager: SessionManager, path: Path) -> None:
         raise AssertionError(f"unexpected session file scan: {path}")
@@ -31,6 +36,23 @@ def test_webui_session_list_reuses_valid_index_without_scanning_files(
 
     assert rows[0]["key"] == "websocket:indexed"
     assert rows[0]["preview"] == "indexed preview"
+    assert rows[0]["model_preset"] == "fast"
+
+
+def test_webui_session_list_rejects_invalid_internal_model_preset_metadata(
+    tmp_path: Path,
+) -> None:
+    manager = SessionManager(tmp_path)
+    session = manager.get_or_create("websocket:custom-metadata")
+    session.metadata["model_preset"] = 7
+    session.metadata[SESSION_MODEL_PRESET_METADATA_KEY] = {"invalid": True}
+    session.add_message("user", "custom metadata")
+    manager.save(session)
+
+    with pytest.raises(ValueError, match="session model preset must be a non-empty string"):
+        list_webui_sessions(manager)
+
+    assert manager.get_or_create(session.key).metadata["model_preset"] == 7
 
 
 def test_webui_session_list_rescans_only_changed_file(tmp_path: Path, monkeypatch) -> None:

tests/webui/test_settings_api.py

@@ -464,6 +464,26 @@ def test_settings_payload_includes_dynamic_custom_provider(
     assert providers[DYNAMIC_PROVIDER_NAME]["api_base"] == DYNAMIC_PROVIDER_API_BASE
 
 
+def test_settings_payload_resolves_provider_for_each_auto_preset(
+    tmp_path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    config_path = tmp_path / "config.json"
+    config = _dynamic_provider_config()
+    config.model_presets["fast"] = ModelPresetConfig(
+        provider="auto",
+        model=f"{DYNAMIC_PROVIDER_NAME}/gpt-4",
+    )
+    save_config(config, config_path)
+    monkeypatch.setattr("nanobot.config.loader._current_config_path", config_path)
+
+    payload = settings_payload()
+    presets = {row["name"]: row for row in payload["model_presets"]}
+
+    assert presets["fast"]["provider"] == "auto"
+    assert presets["fast"]["resolved_provider"] == DYNAMIC_PROVIDER_NAME
+
+
 def test_settings_payload_groups_opencode_compatibility_alias(tmp_path, monkeypatch) -> None:
     config_path = tmp_path / "config.json"
     save_config(Config(), config_path)