feat(core): seeds without text wait for the first turn

tests/test_conversations.py

@@ -396,8 +396,14 @@ async def test_copy_seed_forks_parent_with_window(world: World) -> None:
         "q6",
         [{"type": "text", "text": "a7"}],
     ]
+    assert (await world.conversations.get(child.external_id)).flags["seed"] == "copy"
+    await world.conversations.post(child, "go")
     await world.settle(child, 1)
     assert ScriptedClient.instances[0].options.resume == child.session_id
+    prompt = ScriptedClient.instances[0].prompts[0]
+    assert prompt.startswith("[сид: copy] branch, ")
+    assert "последние 1 тёрнов" in prompt and prompt.endswith("\n\ngo")
+    assert (await world.conversations.get(child.external_id)).flags["seed"] is None
 
 
 async def test_merge_injects_summary_into_parent(world: World) -> None:

tests/test_telegram.py

@@ -462,13 +462,14 @@ async def test_commands_status_merge_and_new(stack: Stack) -> None:
         frontend="telegram", external_id=f"{USER}/902"
     )
     assert child is not None and child.title == "отчёт"
-    await stack.world.settle(child, 1)
     await asyncio.sleep(0.2)
+    assert await stack.world.conversations.queue.recent(child.id) == []
     assert all(m["thread"] != 902 for m in stack.bot.sent)
     assert all(d["message_thread_id"] != 902 for d in stack.bot.drafts)
     stack.bot.message("первое в новый топик", thread=902)
     reply = await stack.until(lambda: stack.sent_with("первое в новый топик"), what="r")
     assert reply["thread"] == 902
+    assert reply["text"].startswith("ok:[сид: morning] branch «отчёт»")
     assert await stack.tg.mark_topic(child)
     assert stack.bot.topics[-1] == "edit:902:✅ отчёт"