fix: harden events log — non-dict ring entries, off-loop journal reads, no default-config singleton

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_events_journal.py

@@ -220,6 +220,18 @@ def test_filter_events_over_in_memory_ring():
     assert more is True
 
 
+def test_filter_events_skips_non_dict_entries():
+    ring = [
+        {"ts": 1.0, "host": "h", "level": "INFO", "service": None, "message": "a"},
+        "legacy string entry",
+        None,
+        {"ts": 2.0, "host": "h", "level": "INFO", "service": None, "message": "b"},
+    ]
+    events, more = journal.filter_events(reversed(ring), limit=10)
+    assert [e["ts"] for e in events] == [2.0, 1.0]
+    assert more is False
+
+
 # ---- eventlog wiring --------------------------------------------------------