feat(5.22): Saved Searches / Smart Lists — reusable filters for list views

- SavedFilter model with TenantMixin (name, entity_type, filter_criteria JSONB, user_id)
- Routes: GET/POST /saved-filters, DELETE /saved-filters/{id} with RBAC
- Alembic migration 0029_saved_filters creates saved_filters table
- Frontend: SavedFilters.tsx component with save/load/delete UI
- Frontend: api/savedFilters.ts with React Query hooks
- Integrated into ContactsListPage as example
- i18n keys for savedFilters.* in de.json and en.json
- Tests: test_saved_filters.py (9 tests) + SavedFilters.test.tsx (3 tests)
- Registered SavedFilter in conftest.py

alembic/versions/0029_saved_filters.py

@@ -0,0 +1,40 @@
+"""saved_filters table
+
+Revision ID: 0029_saved_filters
+Revises: 0028_user_preferences
+Create Date: 2025-07-23
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+
+# revision identifiers
+revision = "0029_saved_filters"
+down_revision = "0028_user_preferences"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "saved_filters",
+        sa.Column("id", UUID(as_uuid=True), primary_key=True, server_default=sa.text("gen_random_uuid()")),
+        sa.Column("tenant_id", UUID(as_uuid=True), nullable=False),
+        sa.Column("user_id", UUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("name", sa.String(100), nullable=False),
+        sa.Column("entity_type", sa.String(50), nullable=False),
+        sa.Column("filter_criteria", JSONB, nullable=False, server_default=sa.text("'{}'::jsonb")),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint("tenant_id", "user_id", "entity_type", "name", name="uq_saved_filters_tenant_user_entity_name"),
+    )
+    op.create_index("ix_saved_filters_tenant_user", "saved_filters", ["tenant_id", "user_id"])
+    op.create_index("ix_saved_filters_tenant_entity", "saved_filters", ["tenant_id", "entity_type"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_saved_filters_tenant_entity", table_name="saved_filters")
+    op.drop_index("ix_saved_filters_tenant_user", table_name="saved_filters")
+    op.drop_table("saved_filters")