style: fix ruff lint violations across service and tests

Wraps over-long lines, sorts imports, drops an unused local, and bumps the
agent submodule for its own import-sort fix so make check passes.

tests/domain/test_validation.py

@@ -283,7 +283,10 @@ def test_existing_node_can_gain_facets_without_replacing_its_assertion() -> None
 
     existing = NODE
     enriched = NODE.model_copy(
-        update={"updated": NOW + timedelta(minutes=1), "tags": (*NODE.tags, "interactive-storytelling")}
+        update={
+            "updated": NOW + timedelta(minutes=1),
+            "tags": (*NODE.tags, "interactive-storytelling"),
+        },
     )
     draft = ProposalRevision(
         proposal_id="proposal-enrich-facets",