feat(library): add workspace scope filter to library list view

Add a `scope` GET parameter to `library_list` allowing users to filter
libraries by all, global-only, or Daedalus workspace-only. Includes a
filter form in the template, an updated empty state message, and tests
covering each scope branch with mocked Neo4j dependencies.

mnemosyne/library/templates/library/library_list.html

@@ -15,6 +15,18 @@
     </div>
 </div>
 
+<form method="get" class="mb-4 flex flex-wrap gap-3 items-end">
+    <div class="form-control">
+        <label class="label"><span class="label-text">Scope</span></label>
+        <select name="scope" class="select select-bordered select-sm">
+            <option value="all"      {% if scope == "all" %}selected{% endif %}>All libraries</option>
+            <option value="global"   {% if scope == "global" %}selected{% endif %}>Global only</option>
+            <option value="daedalus" {% if scope == "daedalus" %}selected{% endif %}>Daedalus workspaces only</option>
+        </select>
+    </div>
+    <button type="submit" class="btn btn-sm btn-outline">Filter</button>
+</form>
+
 {% if error %}
 <div class="alert alert-warning mb-4">
     <span>{{ error }}</span>
@@ -53,8 +65,12 @@
 {% else %}
     {% if not error %}
     <div class="text-center py-12 opacity-60">
+        {% if scope == "all" %}
         <p class="text-lg">No libraries yet.</p>
         <p class="mt-2">Create your first library to get started.</p>
+        {% else %}
+        <p class="text-lg">No libraries match this filter.</p>
+        {% endif %}
     </div>
     {% endif %}
 {% endif %}

mnemosyne/library/tests/test_views.py

@@ -0,0 +1,92 @@
+"""Tests for the library CRUD HTML views.
+
+Currently covers ``library_list``'s Daedalus-workspace scope filter. The
+view loads every ``Library`` node from Neo4j and narrows it by a ``scope``
+GET param (``all`` / ``global`` / ``daedalus``). These tests stub out
+Neo4j entirely — patching ``neo4j_available`` and injecting a fake
+``Library`` class via ``sys.modules`` — so they assert on the queryset
+``.filter(...)`` call the view makes and the context it renders, not on
+real graph behaviour. Mirrors the mocking style in
+``test_search_views_admin_scope.py``.
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.urls import reverse
+
+User = get_user_model()
+
+
+class LibraryListScopeFilterTests(TestCase):
+    """Cover the ``scope`` filter branches of ``library_list``."""
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username="op", email="op@example.com", password="pw"
+        )
+        self.client.force_login(self.user)
+        self.url = reverse("library:library-list")
+
+    def _fake_library_cls(self):
+        """Return (Library stub, nodes mock) where ``nodes`` chains fluently.
+
+        ``Library.nodes`` → ``.filter(...)`` → ``.order_by(...)`` all return
+        the same MagicMock so the view's queryset building works regardless
+        of which branch it takes, and ``.filter`` records its kwargs.
+        """
+        fake_nodes = MagicMock()
+        fake_nodes.filter.return_value = fake_nodes
+        fake_nodes.order_by.return_value = []
+        return SimpleNamespace(nodes=fake_nodes), fake_nodes
+
+    def _get(self, fake_library_cls, **params):
+        with patch("library.views.neo4j_available", return_value=True), \
+             patch.dict(
+                 "sys.modules",
+                 {"library.models": SimpleNamespace(Library=fake_library_cls)},
+             ):
+            return self.client.get(self.url, params)
+
+    def test_default_scope_is_all_and_does_not_filter(self):
+        fake_cls, fake_nodes = self._fake_library_cls()
+        response = self._get(fake_cls)
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.context["scope"], "all")
+        fake_nodes.filter.assert_not_called()
+        fake_nodes.order_by.assert_called_once_with("name")
+
+    def test_global_scope_filters_workspace_isnull_true(self):
+        fake_cls, fake_nodes = self._fake_library_cls()
+        response = self._get(fake_cls, scope="global")
+
+        self.assertEqual(response.context["scope"], "global")
+        fake_nodes.filter.assert_called_once_with(workspace_id__isnull=True)
+
+    def test_daedalus_scope_filters_workspace_isnull_false(self):
+        fake_cls, fake_nodes = self._fake_library_cls()
+        response = self._get(fake_cls, scope="daedalus")
+
+        self.assertEqual(response.context["scope"], "daedalus")
+        fake_nodes.filter.assert_called_once_with(workspace_id__isnull=False)
+
+    def test_unknown_scope_does_not_filter(self):
+        """An unexpected scope value degrades to the unfiltered list."""
+        fake_cls, fake_nodes = self._fake_library_cls()
+        response = self._get(fake_cls, scope="bogus")
+
+        self.assertEqual(response.context["scope"], "bogus")
+        fake_nodes.filter.assert_not_called()
+
+    def test_neo4j_unavailable_sets_error_and_empty_list(self):
+        with patch("library.views.neo4j_available", return_value=False):
+            response = self.client.get(self.url)
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(list(response.context["libraries"]), [])
+        self.assertEqual(response.context["error"], "Neo4j is not available.")

mnemosyne/library/views.py

@@ -31,14 +31,20 @@ logger = logging.getLogger(__name__)
 
 @login_required
 def library_list(request):
-    """List all libraries."""
+    """List libraries, optionally filtered by Daedalus-workspace scope."""
+    scope = request.GET.get("scope", "all")
     libraries = []
     error = None
     if neo4j_available():
         try:
             from .models import Library
 
-            libraries = Library.nodes.order_by("name")
+            qs = Library.nodes
+            if scope == "daedalus":
+                qs = qs.filter(workspace_id__isnull=False)
+            elif scope == "global":
+                qs = qs.filter(workspace_id__isnull=True)
+            libraries = qs.order_by("name")
         except Exception as e:
             error = f"Could not connect to Neo4j: {e}"
             logger.error(error)
@@ -47,7 +53,7 @@ def library_list(request):
     return render(
         request,
         "library/library_list.html",
-        {"libraries": libraries, "error": error},
+        {"libraries": libraries, "error": error, "scope": scope},
     )