feat: goal 模式新语义——prompt 即目标，无验收命令，不限轮次，模型宣告完成 (#67)

console 打勾 goal 模式时不再有专用 goal 文本、验收命令、轮次
三个输入（已移除，换成说明行），只发 goal_mode=1；server 侧
goal_mode=1 时 goal 存 prompt、验收命令空、轮次存 0，带验收
命令或与计划模式同用时 400，旧的带验收命令任务照原样可用。

host.py goal 循环：verify 为空时不跑验测，轮次提示里写明
标记约定；模型在完整跑完的回合末尾单独一行输出“目标已
达成”即达标（超时回合的部分文本含标记也不算）；--max-rounds
0 为不限轮次，goal-resume 续跑按 0 处理（不用 or 兜底成 3）。
刹车只有取消与预算耗尽（后者记 interrupted、可续跑）。

迁移与 worker：tasks 加 goal_mode 列（server 迁移、worker 列
补齐、PG schema 三处同步）；worker 按 goal_mode 或
verify_command 判定 goal 路径，重试与后续消息排空对新语义
同样只跑一次/不排空；Local/Docker goal_task 的 --verify 可选、
--max-rounds 0 原样传。

Co-authored-by: host <host@test.local>

tests/test_host.py

@@ -889,6 +889,97 @@ class GoalLoopLongTaskTest(unittest.TestCase):
             self.assertEqual(task["status"], "goal-unmet")
             self.assertIn("verify timeout", task["goal_last_verify"])
 
+    def test_goal_llm_decided_met_on_marker_unlimited(self):
+        # 新形态：verify=None、max_rounds=0（不限轮次）；首轮提示
+        # 含标记约定；第 2 轮模型输出标记行即达标。
+        class FakeServer:
+            def __init__(self):
+                self.prompts = []
+
+            def run_turn(self, thread_id, prompt, model=None, effort=None,
+                         sandbox=None, timeout=None):
+                self.prompts.append(prompt)
+                if len(self.prompts) == 1:
+                    return {"status": "completed", "text": "working",
+                            "turn_id": "u1"}
+                return {"status": "completed",
+                        "text": "done\n目标已达成",
+                        "turn_id": "u2"}
+
+        with tempfile.TemporaryDirectory() as tmp:
+            state_path = os.path.join(tmp, "host-state.json")
+            state = {"tasks": {}, "automations": []}
+            task = self._task(tmp)
+            state["tasks"]["g"] = task
+            srv = FakeServer()
+            result = host.run_goal_loop(srv, state, state_path,
+                                        task, "make it", None, 0, "m",
+                                        "low", None, cfg={}, timeout=600)
+            self.assertTrue(result["ok"])
+            self.assertEqual(task["status"], "goal-met")
+            self.assertEqual(task["goal_rounds_done"], 2)
+            self.assertEqual(task["goal_max_rounds"], 0)
+            self.assertIn("目标已达成", srv.prompts[0])
+            self.assertIn("目标已达成", srv.prompts[1])
+
+    def test_goal_llm_decided_marker_ignored_on_timeout_turn(self):
+        # 超时回合的部分文本即使含标记行也不算达标，必须继续跑。
+        class FakeServer:
+            def __init__(self):
+                self.calls = 0
+
+            def run_turn(self, thread_id, prompt, model=None, effort=None,
+                         sandbox=None, timeout=None):
+                self.calls += 1
+                if self.calls == 1:
+                    return {"status": "timeout",
+                            "text": "partial\n目标已达成",
+                            "turn_id": "u1"}
+                return {"status": "completed",
+                        "text": "done\n目标已达成",
+                        "turn_id": "u2"}
+
+        with tempfile.TemporaryDirectory() as tmp:
+            state_path = os.path.join(tmp, "host-state.json")
+            state = {"tasks": {}, "automations": []}
+            task = self._task(tmp)
+            state["tasks"]["g"] = task
+            result = host.run_goal_loop(FakeServer(), state, state_path,
+                                        task, "make it", None, 0, "m",
+                                        "low", None, cfg={}, timeout=600)
+            self.assertTrue(result["ok"])
+            self.assertEqual(task["status"], "goal-met")
+            self.assertEqual(task["goal_rounds_done"], 2)
+
+    def test_goal_llm_decided_unlimited_past_three_rounds(self):
+        # 0 = 不限轮次：第 4 轮才宣告也照常结束，不会被旧的
+        # 默认 3 轮上限截断。
+        class FakeServer:
+            def __init__(self):
+                self.calls = 0
+
+            def run_turn(self, thread_id, prompt, model=None, effort=None,
+                         sandbox=None, timeout=None):
+                self.calls += 1
+                if self.calls < 4:
+                    return {"status": "completed", "text": "working",
+                            "turn_id": "u%d" % self.calls}
+                return {"status": "completed",
+                        "text": "done\n目标已达成",
+                        "turn_id": "u4"}
+
+        with tempfile.TemporaryDirectory() as tmp:
+            state_path = os.path.join(tmp, "host-state.json")
+            state = {"tasks": {}, "automations": []}
+            task = self._task(tmp)
+            state["tasks"]["g"] = task
+            result = host.run_goal_loop(FakeServer(), state, state_path,
+                                        task, "make it", None, 0, "m",
+                                        "low", None, cfg={}, timeout=600)
+            self.assertTrue(result["ok"])
+            self.assertEqual(task["status"], "goal-met")
+            self.assertEqual(task["goal_rounds_done"], 4)
+
 
 
 class ProgressInterruptTest(unittest.TestCase):