feat(backend): gate Other Models behind opt-in management toggles

Other Models management is now opt-in: enable_other_models (default false)
plus the enabled_other_sub_types allow-list replace the unreleased additive
enabled_other_folders key.

- config._get_enabled_other_folder_keys() is the single scan gate; a new
  refresh_other_roots() rebuilds roots and preview roots on toggle.
- ModelScanner gains a _should_keep_cached_entry() hydration hook and
  on_library_changed(reconcile=...) so switching a sub_type off drops its
  entries (and hash/autov3 rows) at load time and switching it on rescans.
- OtherScanner filters location-derived entries accordingly.
- Other routes reject every other type while off (or a disabled sub_type) and
  expose an "other_disabled" page flag; download routing returns a disabled
  marker instead of guessing; the download manager refuses other-type
  downloads and default-path routing for switched-off sub_types.
- Doctor / init-status / refresh-all skip the other scanner while off; the
  scanner stays registered so staged pending-deletes still merge.
- Tests updated with explicit opt-in fixtures plus new gating coverage.

tests/config/test_other_paths.py

@@ -26,6 +26,14 @@ def _make_config(**overrides) -> config_module.Config:
     return config
 
 
+@pytest.fixture(autouse=True)
+def enable_other_models():
+    """Other Models is opt-in; enable it for the enabled-state tests."""
+    manager = get_settings_manager()
+    manager.set("enable_other_models", True)
+    yield
+
+
 class TestPrepareOtherPaths:
     """Unit tests for Config._prepare_other_paths."""
 
@@ -196,7 +204,7 @@ class TestInitOtherPaths:
         controlnet_dir.mkdir()
 
         self._stub_folder_paths(monkeypatch, {"controlnet": str(controlnet_dir)})
-        get_settings_manager().set("enabled_other_folders", ["controlnet"])
+        get_settings_manager().set("enabled_other_sub_types", ["controlnet"])
 
         config = _make_config()
         roots = config._init_other_paths()
@@ -207,12 +215,45 @@ class TestInitOtherPaths:
             == "controlnet"
         )
 
+    def test_disabled_sub_type_is_not_scanned(self, monkeypatch, tmp_path):
+        vae_dir = tmp_path / "vae"
+        upscaler_dir = tmp_path / "upscale_models"
+        vae_dir.mkdir()
+        upscaler_dir.mkdir()
+
+        self._stub_folder_paths(
+            monkeypatch, {"vae": str(vae_dir), "upscale_models": str(upscaler_dir)}
+        )
+        get_settings_manager().set("enabled_other_sub_types", ["vae"])
+
+        config = _make_config()
+        roots = config._init_other_paths()
+
+        assert roots == [_normalize(str(vae_dir))]
+        assert _normalize(str(upscaler_dir)) not in config.other_root_subtypes
+
+    def test_feature_disabled_scans_nothing(self, monkeypatch, tmp_path):
+        vae_dir = tmp_path / "vae"
+        vae_dir.mkdir()
+
+        self._stub_folder_paths(monkeypatch, {"vae": str(vae_dir)})
+        get_settings_manager().set("enable_other_models", False)
+
+        config = _make_config()
+        roots = config._init_other_paths()
+
+        assert roots == []
+        assert config.other_root_subtypes == {}
+        assert config.other_folder_roots == {}
+
     def test_unknown_opt_in_keys_are_ignored(self, monkeypatch, tmp_path):
         vae_dir = tmp_path / "vae"
         vae_dir.mkdir()
 
         self._stub_folder_paths(monkeypatch, {"vae": str(vae_dir)})
-        get_settings_manager().set("enabled_other_folders", ["not_a_real_key", 42])
+        get_settings_manager().set(
+            "enabled_other_sub_types", ["vae", "not_a_real_key", 42]
+        )
 
         config = _make_config()
         roots = config._init_other_paths()

tests/routes/test_download_routing_handlers.py

@@ -5,6 +5,22 @@ import json
 import pytest
 
 from py.routes.handlers.download_routing_handlers import DownloadRoutingHandler
+from py.services.settings_manager import get_settings_manager
+
+
+@pytest.fixture(autouse=True)
+def enable_other_models():
+    """Other Models is opt-in; enable every sub_type for the routing tests."""
+    manager = get_settings_manager()
+    manager.settings["enable_other_models"] = True
+    manager.settings["enabled_other_sub_types"] = [
+        "vae",
+        "upscaler",
+        "text_encoder",
+        "clip_vision",
+        "controlnet",
+    ]
+    yield
 
 
 class FakeRequest:
@@ -149,3 +165,32 @@ async def test_other_invalid_selected_file_type_rejected():
         FakeRequest({"model_type": "VAE", "selected_file_type": 123})
     )
     assert response.status == 400
+
+
+@pytest.mark.asyncio
+async def test_other_routing_disabled_when_feature_off():
+    get_settings_manager().settings["enable_other_models"] = False
+
+    handler = DownloadRoutingHandler()
+    response = await handler.get_download_routing(
+        FakeRequest({"model_type": "VAE", "file_types": ["Model"]})
+    )
+    payload = json.loads(response.text)
+    assert payload["sub_type"] is None
+    assert payload["disabled"] is True
+    assert payload["reason"] == "other_models_disabled"
+
+
+@pytest.mark.asyncio
+async def test_other_routing_disabled_for_switched_off_sub_type():
+    get_settings_manager().settings["enabled_other_sub_types"] = ["vae"]
+
+    handler = DownloadRoutingHandler()
+    response = await handler.get_download_routing(
+        FakeRequest({"model_type": "Upscaler", "file_types": ["Model"]})
+    )
+    payload = json.loads(response.text)
+    assert payload["sub_type"] is None
+    assert payload["disabled"] is True
+    assert payload["reason"] == "other_sub_type_disabled"
+    assert payload["requested_sub_type"] == "upscaler"

tests/routes/test_misc_routes.py

@@ -61,6 +61,12 @@ class DummySettings:
     def get(self, key, default=None):
         return self.data.get(key, default)
 
+    def is_other_models_enabled(self):
+        return bool(self.data.get("enable_other_models", False))
+
+    def get_enabled_other_sub_types(self):
+        return list(self.data.get("enabled_other_sub_types") or [])
+
     def set(self, key, value):
         self.data[key] = value
 

tests/routes/test_other_routes.py

@@ -30,6 +30,20 @@ def routes():
     return handler
 
 
+@pytest.fixture(autouse=True)
+def enable_other_models():
+    """Other Models is opt-in; these tests exercise the enabled state."""
+    from py.services.settings_manager import get_settings_manager
+
+    manager = get_settings_manager()
+    manager.set("enable_other_models", True)
+    manager.set(
+        "enabled_other_sub_types",
+        ["vae", "upscaler", "text_encoder", "clip_vision", "controlnet"],
+    )
+    yield
+
+
 def test_common_and_specific_routes_registered():
     """Registration smoke test: /api/lm/other/* surface plus the /other page."""
     app = web.Application()
@@ -64,6 +78,39 @@ def test_validate_civitai_model_type_rejects_foreign_types(model_type):
     assert OtherRoutes()._validate_civitai_model_type(model_type) is False
 
 
+def test_validate_rejects_everything_when_feature_disabled():
+    from py.services.settings_manager import get_settings_manager
+
+    get_settings_manager().set("enable_other_models", False)
+
+    handler = OtherRoutes()
+    for model_type in ("VAE", "Upscaler", "TextEncoder", "CLIPVision", "Other"):
+        assert handler._validate_civitai_model_type(model_type) is False
+
+
+def test_validate_rejects_switched_off_sub_type():
+    from py.services.settings_manager import get_settings_manager
+
+    get_settings_manager().set("enabled_other_sub_types", ["vae"])
+
+    handler = OtherRoutes()
+    assert handler._validate_civitai_model_type("VAE") is True
+    assert handler._validate_civitai_model_type("Upscaler") is False
+
+
+def test_page_context_reports_feature_state():
+    from py.services.settings_manager import get_settings_manager
+
+    manager = get_settings_manager()
+    handler = OtherRoutes()
+    provider = handler._get_page_context_provider()
+
+    assert provider(None) == {"other_disabled": False}
+
+    manager.set("enable_other_models", False)
+    assert provider(None) == {"other_disabled": True}
+
+
 def test_get_expected_model_types_mentions_supported_types():
     expected = OtherRoutes()._get_expected_model_types()
     for name in ("VAE", "Upscaler", "TextEncoder", "CLIPVision", "Controlnet"):

tests/services/test_download_manager_other.py

@@ -43,6 +43,14 @@ def isolate_settings(monkeypatch, tmp_path):
                 "text_encoder": str(tmp_path / "text_encoders"),
                 "clip_vision": str(tmp_path / "clip_vision"),
             },
+            "enable_other_models": True,
+            "enabled_other_sub_types": [
+                "vae",
+                "upscaler",
+                "text_encoder",
+                "clip_vision",
+                "controlnet",
+            ],
             "download_path_templates": {
                 "lora": "{base_model}/{first_tag}",
                 "checkpoint": "{base_model}/{first_tag}",
@@ -231,6 +239,40 @@ async def test_download_rejects_unknown_model_type(
     assert result["error"].startswith("Model type")
 
 
+@pytest.mark.asyncio
+async def test_download_rejects_other_when_feature_disabled(
+    monkeypatch, scanners, metadata_provider, tmp_path
+):
+    """The opt-in feature is off: no other-type download is accepted."""
+    metadata_provider.payload = _other_payload("VAE")
+    get_settings_manager().settings["enable_other_models"] = False
+
+    manager = DownloadManager()
+    result = await manager.download_from_civitai(
+        model_version_id=99, save_dir=str(tmp_path)
+    )
+
+    assert result["success"] is False
+    assert "disabled" in result["error"].lower()
+
+
+@pytest.mark.asyncio
+async def test_default_paths_reject_switched_off_sub_type(
+    monkeypatch, scanners, metadata_provider, tmp_path
+):
+    """A disabled sub_type refuses default-path routing (manual pick still works)."""
+    metadata_provider.payload = _other_payload("VAE")
+    get_settings_manager().settings["enabled_other_sub_types"] = ["upscaler"]
+
+    manager = DownloadManager()
+    result = await manager.download_from_civitai(
+        model_version_id=99, use_default_paths=True
+    )
+
+    assert result["success"] is False
+    assert "disabled" in result["error"].lower()
+
+
 @pytest.mark.asyncio
 async def test_early_gate_checks_other_scanner(
     monkeypatch, scanners, metadata_provider, tmp_path

tests/services/test_other_scanner.py

@@ -173,6 +173,51 @@ class TestOtherScannerRoots:
         assert result["sub_type"] == "upscaler"
 
 
+class TestOtherScannerHydrationFilter:
+    """Persisted entries for roots that are no longer managed are dropped."""
+
+    def test_keeps_entries_under_enabled_roots(self, other_config):
+        scanner = _make_scanner()
+        assert (
+            scanner._should_keep_cached_entry(
+                {"file_path": f"{other_config['vae']}/model.safetensors"}
+            )
+            is True
+        )
+
+    def test_drops_entries_under_disabled_root(self, other_config, monkeypatch):
+        scanner = _make_scanner()
+        # Only vae stays managed; the upscaler root disappeared from the map.
+        monkeypatch.setattr(
+            config_module.config,
+            "other_root_subtypes",
+            {other_config["vae"]: "vae"},
+        )
+
+        assert (
+            scanner._should_keep_cached_entry(
+                {"file_path": f"{other_config['upscaler']}/model.safetensors"}
+            )
+            is False
+        )
+        assert (
+            scanner._should_keep_cached_entry(
+                {"file_path": f"{other_config['vae']}/model.safetensors"}
+            )
+            is True
+        )
+
+    def test_drops_everything_when_feature_off(self, monkeypatch):
+        monkeypatch.setattr(config_module.config, "other_root_subtypes", {})
+        scanner = _make_scanner()
+        assert (
+            scanner._should_keep_cached_entry(
+                {"file_path": "/models/vae/model.safetensors"}
+            )
+            is False
+        )
+
+
 class TestOtherScannerLazyHash:
     """Lazy hashing: pending by default, singleflight on-demand calculation."""
 

tests/services/test_recipe_scanner.py

@@ -2513,7 +2513,7 @@ async def test_on_library_changed_bumps_cache_version(tmp_path: Path, monkeypatc
     scanner = DummyScanner(str(tmp_path))
     assert scanner.cache_version == 0
 
-    async def _noop_initialize() -> None:
+    async def _noop_initialize(reconcile: bool = False) -> None:
         pass
 
     monkeypatch.setattr(scanner, "initialize_in_background", _noop_initialize)

tests/services/test_settings_manager.py

@@ -1222,7 +1222,33 @@ def test_default_other_roots_stay_empty_without_other_folders(manager):
     assert manager.get("default_other_roots") == {}
 
 
+def test_other_models_disabled_by_default(manager):
+    assert manager.is_other_models_enabled() is False
+    assert manager.get_enabled_other_sub_types() == []
+    assert manager.is_other_sub_type_enabled("vae") is False
+
+
+def test_auto_set_default_other_roots_skipped_when_feature_off(manager):
+    manager.settings["enable_other_models"] = False
+    manager.settings["default_other_roots"] = {}
+    manager.settings["folder_paths"] = {"vae": ["/vae"]}
+
+    manager._auto_set_default_roots()
+
+    assert manager.get("default_other_roots") == {}
+
+
+def test_set_enabled_other_sub_types_normalizes(manager):
+    manager.settings["enable_other_models"] = True
+    manager.set("enabled_other_sub_types", ["controlnet", "vae", "nope", "vae", 42])
+
+    assert manager.get("enabled_other_sub_types") == ["vae", "controlnet"]
+    assert manager.is_other_sub_type_enabled("vae") is True
+    assert manager.is_other_sub_type_enabled("upscaler") is False
+
+
 def test_auto_set_default_other_roots(manager):
+    manager.settings["enable_other_models"] = True
     manager.settings["default_other_roots"] = {}
     manager.settings["folder_paths"] = {
         "vae": ["/vae"],
@@ -1243,6 +1269,7 @@ def test_auto_set_default_other_roots(manager):
 
 def test_auto_set_default_other_roots_text_encoder_dual_key_union(manager):
     """text_encoder candidates merge text_encoders and the legacy clip key."""
+    manager.settings["enable_other_models"] = True
     manager.settings["default_other_roots"] = {}
     manager.settings["folder_paths"] = {
         "clip": ["/legacy-clip"],
@@ -1261,6 +1288,7 @@ def test_auto_set_default_other_roots_text_encoder_dual_key_union(manager):
 
 
 def test_auto_set_default_other_roots_repairs_stale(manager):
+    manager.settings["enable_other_models"] = True
     manager.settings["default_other_roots"] = {"vae": "/stale-vae"}
     manager.settings["folder_paths"] = {"vae": ["/vae"]}
 
@@ -1270,6 +1298,7 @@ def test_auto_set_default_other_roots_repairs_stale(manager):
 
 
 def test_auto_set_default_other_roots_uses_extra_folder_paths(manager):
+    manager.settings["enable_other_models"] = True
     manager.settings["default_other_roots"] = {}
     manager.settings["folder_paths"] = {"vae": []}
     manager.settings["extra_folder_paths"] = {"vae": ["/extra-vae"]}