style: ruff format + stronger sqlite asserts (delete utils, drop test_no_gng)

tests/test_store_sqlite.py

@@ -1,18 +1,24 @@
-import tempfile, pathlib
+import pathlib
+import tempfile
+
 from agentmsgs.stores.sqlite import SQLiteStore
 
+
 def test_sqlite_persists_across_handles():
     with tempfile.TemporaryDirectory() as d:
-        p = pathlib.Path(d)/"test.db"
+        p = pathlib.Path(d) / "test.db"
         s1 = SQLiteStore(p)
         try:
-            a = s1.get_or_create_agent("Alice"); b = s1.get_or_create_agent("Bob")
-            t = s1.create_thread({a,b})
+            a = s1.get_or_create_agent("Alice")
+            b = s1.get_or_create_agent("Bob")
+            t = s1.create_thread({a, b})
             s1.append_message(t.id, a, "hi")
             # new handle same file
             s2 = SQLiteStore(p)
             try:
-                assert s2.get_agent_by_name("Alice").id == a.id
+                a2 = s2.get_agent_by_name("Alice")
+                assert a2 is not None
+                assert a2.id == a.id
                 assert len(s2.list_messages(t.id)) == 1
                 assert s2.find_threads({a})[0].id == t.id
             finally:
@@ -20,17 +26,28 @@ def test_sqlite_persists_across_handles():
         finally:
             s1.close()
 
+
 def test_sqlite_concurrent_append():
-    import pathlib, tempfile
+    import pathlib
+    import tempfile
+
     from agentmsgs.stores.sqlite import SQLiteStore
+
     with tempfile.TemporaryDirectory() as d:
-        p = pathlib.Path(d)/"c.db"
-        s1 = SQLiteStore(p); s2 = SQLiteStore(p)
+        p = pathlib.Path(d) / "c.db"
+        s1 = SQLiteStore(p)
+        s2 = SQLiteStore(p)
         try:
-            a = s1.get_or_create_agent("A"); b = s1.get_or_create_agent("B")
+            a = s1.get_or_create_agent("A")
+            b = s1.get_or_create_agent("B")
             # s2 sees same agents via file
-            a2 = s2.get_agent_by_name("A"); b2 = s2.get_agent_by_name("B")
-            t = s1.create_thread({a,b})
+            a2 = s2.get_agent_by_name("A")
+            b2 = s2.get_agent_by_name("B")
+            assert a2 is not None
+            assert b2 is not None
+            assert a.id == a2.id
+            assert b.id == b2.id
+            t = s1.create_thread({a, b})
             s1.append_message(t.id, a, "from s1")
             s2.append_message(t.id, b2, "from s2")
             assert len(s1.list_messages(t.id)) == 2