fix: final review — atomic sqlite seq, remove shims and legacy types, cleanup

tests/test_store_sqlite.py

@@ -5,14 +5,20 @@ def test_sqlite_persists_across_handles():
     with tempfile.TemporaryDirectory() as d:
         p = pathlib.Path(d)/"test.db"
         s1 = SQLiteStore(p)
-        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)
-        assert s2.get_agent_by_name("Alice").id == a.id
-        assert len(s2.list_messages(t.id)) == 1
-        assert s2.find_threads({a})[0].id == t.id
+        try:
+            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
+                assert len(s2.list_messages(t.id)) == 1
+                assert s2.find_threads({a})[0].id == t.id
+            finally:
+                s2.close()
+        finally:
+            s1.close()
 
 def test_sqlite_concurrent_append():
     import pathlib, tempfile
@@ -20,10 +26,19 @@ def test_sqlite_concurrent_append():
     with tempfile.TemporaryDirectory() as d:
         p = pathlib.Path(d)/"c.db"
         s1 = SQLiteStore(p); s2 = SQLiteStore(p)
-        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})
-        s1.append_message(t.id, a, "from s1")
-        s2.append_message(t.id, b2, "from s2")
-        assert len(s1.list_messages(t.id)) == 2
+        try:
+            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})
+            s1.append_message(t.id, a, "from s1")
+            s2.append_message(t.id, b2, "from s2")
+            assert len(s1.list_messages(t.id)) == 2
+            # verify seq uniqueness and monotonicity
+            msgs = s1.list_messages(t.id)
+            seqs = [m.seq for m in msgs]
+            assert seqs == [1, 2]
+            assert len(set(seqs)) == 2
+        finally:
+            s2.close()
+            s1.close()