chore(ei-parity): empty known-deltas registry + fix anonymous deadCount parity

libs/gw2_analytics/src/gw2_analytics/ei_compare.py

@@ -737,6 +737,12 @@ def player_agent_ids(agent: Agent, slice_lo: int = 0, slice_hi: int = 0) -> set[
         if not agent.instance_id:
             return {agent.id}
         entries = agents_by_instance_entries.get(agent.instance_id, [])
+        if agent.account_name is None:
+            # Non Squad Player: EI groups every anonymous agent sharing the
+            # instance into one entity, even when a named agent recycles it
+            anonymous = {entry.id for entry in entries if entry.account_name is None}
+            if len(anonymous) > 1:
+                return anonymous
         accounts = {entry.account_name for entry in entries}
         if len(accounts) > 1:
             return {agent.id}

libs/gw2_analytics/tests/test_ei_compare.py

@@ -2,8 +2,6 @@
 
 from typing import Any, cast
 
-import pytest
-
 from gw2_analytics.ei_compare import _skill_stats, compare_elite_insights
 from gw2_core import (
     Agent,
@@ -23,7 +21,6 @@ def _rows(result: dict[str, object]) -> dict[str, dict[str, Any]]:
     return {str(row["key"]): row for row in cast("list[dict[str, Any]]", result["results"])}
 
 
-@pytest.mark.skip(reason="Pre-existing flaky test - deadCount mismatch for Non Squad Player 5")
 def test_compare_elite_insights_keeps_first_anonymous_agent_for_shared_instance() -> None:
     fight = Fight(
         id="fight",