feat: Add extra folder paths support for LoRA Manager

Introduce extra_folder_paths feature to allow users to add additional
model roots that are managed by LoRA Manager but not shared with ComfyUI.

Changes:
- Add extra_folder_paths support in SettingsManager (stored per library)
- Add extra path attributes in Config class (extra_loras_roots, etc.)
- Merge folder_paths with extra_folder_paths when applying library settings
- Update LoraScanner, CheckpointScanner, EmbeddingScanner to include
  extra paths in their model roots
- Add comprehensive tests for the new functionality

This enables users to manage models from additional directories without
modifying ComfyUI's model folder configuration.

tests/config/test_config_save_paths.py

@@ -215,3 +215,110 @@ def test_save_paths_removes_template_default_library(monkeypatch, tmp_path):
     )
     assert payload["metadata"] == {"display_name": "ComfyUI", "source": "comfyui"}
     assert payload["activate"] is True
+
+
+def test_apply_library_settings_merges_extra_paths(monkeypatch, tmp_path):
+    """Test that apply_library_settings correctly merges folder_paths with extra_folder_paths."""
+    loras_dir = tmp_path / "loras"
+    extra_loras_dir = tmp_path / "extra_loras"
+    checkpoints_dir = tmp_path / "checkpoints"
+    extra_checkpoints_dir = tmp_path / "extra_checkpoints"
+    embeddings_dir = tmp_path / "embeddings"
+    extra_embeddings_dir = tmp_path / "extra_embeddings"
+
+    for directory in (loras_dir, extra_loras_dir, checkpoints_dir, extra_checkpoints_dir, embeddings_dir, extra_embeddings_dir):
+        directory.mkdir()
+
+    config_instance = config_module.Config()
+
+    folder_paths = {
+        "loras": [str(loras_dir)],
+        "checkpoints": [str(checkpoints_dir)],
+        "unet": [],
+        "embeddings": [str(embeddings_dir)],
+    }
+    extra_folder_paths = {
+        "loras": [str(extra_loras_dir)],
+        "checkpoints": [str(extra_checkpoints_dir)],
+        "unet": [],
+        "embeddings": [str(extra_embeddings_dir)],
+    }
+
+    library_config = {
+        "folder_paths": folder_paths,
+        "extra_folder_paths": extra_folder_paths,
+    }
+
+    config_instance.apply_library_settings(library_config)
+
+    assert str(loras_dir) in config_instance.loras_roots
+    assert str(extra_loras_dir) in config_instance.extra_loras_roots
+    assert str(checkpoints_dir) in config_instance.base_models_roots
+    assert str(extra_checkpoints_dir) in config_instance.extra_checkpoints_roots
+    assert str(embeddings_dir) in config_instance.embeddings_roots
+    assert str(extra_embeddings_dir) in config_instance.extra_embeddings_roots
+
+
+def test_apply_library_settings_without_extra_paths(monkeypatch, tmp_path):
+    """Test that apply_library_settings works when extra_folder_paths is not provided."""
+    loras_dir = tmp_path / "loras"
+    checkpoints_dir = tmp_path / "checkpoints"
+    embeddings_dir = tmp_path / "embeddings"
+
+    for directory in (loras_dir, checkpoints_dir, embeddings_dir):
+        directory.mkdir()
+
+    config_instance = config_module.Config()
+
+    folder_paths = {
+        "loras": [str(loras_dir)],
+        "checkpoints": [str(checkpoints_dir)],
+        "unet": [],
+        "embeddings": [str(embeddings_dir)],
+    }
+
+    library_config = {
+        "folder_paths": folder_paths,
+    }
+
+    config_instance.apply_library_settings(library_config)
+
+    assert str(loras_dir) in config_instance.loras_roots
+    assert config_instance.extra_loras_roots == []
+    assert str(checkpoints_dir) in config_instance.base_models_roots
+    assert config_instance.extra_checkpoints_roots == []
+    assert str(embeddings_dir) in config_instance.embeddings_roots
+    assert config_instance.extra_embeddings_roots == []
+
+
+def test_extra_paths_deduplication(monkeypatch, tmp_path):
+    """Test that extra paths are stored separately from main paths in Config."""
+    loras_dir = tmp_path / "loras"
+    extra_loras_dir = tmp_path / "extra_loras"
+    loras_dir.mkdir()
+    extra_loras_dir.mkdir()
+
+    config_instance = config_module.Config()
+
+    folder_paths = {
+        "loras": [str(loras_dir)],
+        "checkpoints": [],
+        "unet": [],
+        "embeddings": [],
+    }
+    extra_folder_paths = {
+        "loras": [str(extra_loras_dir)],
+        "checkpoints": [],
+        "unet": [],
+        "embeddings": [],
+    }
+
+    library_config = {
+        "folder_paths": folder_paths,
+        "extra_folder_paths": extra_folder_paths,
+    }
+
+    config_instance.apply_library_settings(library_config)
+
+    assert config_instance.loras_roots == [str(loras_dir)]
+    assert config_instance.extra_loras_roots == [str(extra_loras_dir)]

tests/services/test_checkpoint_scanner.py

@@ -132,4 +132,59 @@ async def test_persisted_cache_restores_model_type(tmp_path: Path, monkeypatch):
     assert types_by_path[normalized_unet_file] == "diffusion_model"
 
     assert ws_stub.payloads
-    assert ws_stub.payloads[-1]["stage"] == "loading_cache"
+
+
+@pytest.mark.asyncio
+async def test_checkpoint_scanner_get_model_roots_includes_extra_paths(monkeypatch, tmp_path):
+    """Test that get_model_roots includes both main and extra paths."""
+    checkpoints_root = tmp_path / "checkpoints"
+    extra_checkpoints_root = tmp_path / "extra_checkpoints"
+    unet_root = tmp_path / "unet"
+    extra_unet_root = tmp_path / "extra_unet"
+
+    for directory in (checkpoints_root, extra_checkpoints_root, unet_root, extra_unet_root):
+        directory.mkdir()
+
+    normalized_checkpoints = _normalize(checkpoints_root)
+    normalized_extra_checkpoints = _normalize(extra_checkpoints_root)
+    normalized_unet = _normalize(unet_root)
+    normalized_extra_unet = _normalize(extra_unet_root)
+
+    monkeypatch.setattr(
+        model_scanner.config,
+        "base_models_roots",
+        [normalized_checkpoints, normalized_unet],
+        raising=False,
+    )
+    monkeypatch.setattr(
+        model_scanner.config,
+        "checkpoints_roots",
+        [normalized_checkpoints],
+        raising=False,
+    )
+    monkeypatch.setattr(
+        model_scanner.config,
+        "unet_roots",
+        [normalized_unet],
+        raising=False,
+    )
+    monkeypatch.setattr(
+        model_scanner.config,
+        "extra_checkpoints_roots",
+        [normalized_extra_checkpoints],
+        raising=False,
+    )
+    monkeypatch.setattr(
+        model_scanner.config,
+        "extra_unet_roots",
+        [normalized_extra_unet],
+        raising=False,
+    )
+
+    scanner = CheckpointScanner()
+    roots = scanner.get_model_roots()
+
+    assert normalized_checkpoints in roots
+    assert normalized_unet in roots
+    assert normalized_extra_checkpoints in roots
+    assert normalized_extra_unet in roots

tests/services/test_settings_manager.py

@@ -470,6 +470,100 @@ def test_upsert_library_creates_entry_and_activates(manager, tmp_path):
     assert str(lora_dir).replace(os.sep, "/") in normalized_stored_paths
 
 
+def test_extra_folder_paths_stored_separately(manager, tmp_path):
+    lora_dir = tmp_path / "loras"
+    extra_dir = tmp_path / "extra_loras"
+    lora_dir.mkdir()
+    extra_dir.mkdir()
+
+    manager.upsert_library(
+        "test_library",
+        folder_paths={"loras": [str(lora_dir)]},
+        extra_folder_paths={"loras": [str(extra_dir)]},
+        activate=True,
+    )
+
+    libraries = manager.get_libraries()
+    lib = libraries["test_library"]
+
+    # Verify folder_paths contains main path
+    assert str(lora_dir) in lib["folder_paths"]["loras"]
+    # Verify extra_folder_paths contains extra path
+    assert str(extra_dir) in lib["extra_folder_paths"]["loras"]
+    # Verify they are separate
+    assert str(extra_dir) not in lib["folder_paths"]["loras"]
+
+
+def test_get_extra_folder_paths(manager, tmp_path):
+    extra_dir = tmp_path / "extra_loras"
+    extra_dir.mkdir()
+
+    manager.update_extra_folder_paths({"loras": [str(extra_dir)]})
+
+    extra_paths = manager.get_extra_folder_paths()
+    assert str(extra_dir) in extra_paths.get("loras", [])
+
+
+def test_library_switch_preserves_extra_paths(manager, tmp_path):
+    """Test that switching libraries preserves each library's extra paths."""
+    lora_dir1 = tmp_path / "lib1_loras"
+    extra_dir1 = tmp_path / "lib1_extra"
+    lora_dir2 = tmp_path / "lib2_loras"
+    extra_dir2 = tmp_path / "lib2_extra"
+
+    for directory in (lora_dir1, extra_dir1, lora_dir2, extra_dir2):
+        directory.mkdir()
+
+    manager.create_library(
+        "library1",
+        folder_paths={"loras": [str(lora_dir1)]},
+        extra_folder_paths={"loras": [str(extra_dir1)]},
+        activate=True,
+    )
+
+    manager.create_library(
+        "library2",
+        folder_paths={"loras": [str(lora_dir2)]},
+        extra_folder_paths={"loras": [str(extra_dir2)]},
+    )
+
+    assert manager.get_active_library_name() == "library1"
+    lib1 = manager.get_active_library()
+    assert str(lora_dir1) in lib1["folder_paths"]["loras"]
+    assert str(extra_dir1) in lib1["extra_folder_paths"]["loras"]
+
+    manager.activate_library("library2")
+
+    assert manager.get_active_library_name() == "library2"
+    lib2 = manager.get_active_library()
+    assert str(lora_dir2) in lib2["folder_paths"]["loras"]
+    assert str(extra_dir2) in lib2["extra_folder_paths"]["loras"]
+
+
+def test_extra_paths_validation_no_overlap_with_other_libraries(manager, tmp_path):
+    """Test that extra paths cannot overlap with other libraries' paths."""
+    lora_dir1 = tmp_path / "lib1_loras"
+    lora_dir1.mkdir()
+
+    manager.create_library(
+        "library1",
+        folder_paths={"loras": [str(lora_dir1)]},
+        activate=True,
+    )
+
+    extra_dir = tmp_path / "extra_loras"
+    extra_dir.mkdir()
+
+    manager.create_library(
+        "library2",
+        folder_paths={"loras": [str(extra_dir)]},
+        activate=True,
+    )
+
+    with pytest.raises(ValueError, match="already assigned to library"):
+        manager.update_extra_folder_paths({"loras": [str(lora_dir1)]})
+
+
 def test_delete_library_switches_active(manager, tmp_path):
     other_dir = tmp_path / "other"
     other_dir.mkdir()