feat: 旧任务继续会话——终端任务带新消息 + 全部选项同一会话续跑

server：POST /tasks/{id}/continue（终端非 merged 任务重排队，
resume_message 列存本轮消息，不传选项沿用原值，plan/goal 冲突
与新建一致，goal_mode=1 时转新 goal 语义；CAS 防并发改状态，
审计 task_continued）；tasks.resume_message 三处迁移 + PG 建表。
worker：认领后本轮 prompt 换成续跑消息（只换内存副本），
goal 续跑走 goal-resume 而不是 goal，跑完清 resume_message
（进程被杀时不清，下次认领重跑同一条消息）。
host：goal-resume --goal-text（旧任务接续 goal 模式：跳过状态
与记录守卫，旧线程上从第 1 轮开新目标循环，新语义不限轮次；
无线程时拒绝）。
sandbox：Local/Docker goal_resume_task + popen goal-resume kind；
附带 popen goal 命令改成新语义（无验收不传 --verify，轮次 0
原样传，此前 goal 任务到本地 worker 会直接报错）。
console：详情页终端非 merged 任务出继续会话表单（消息 +
模型/强度/权限/计划/goal，模型下拉复用中转列表）。
测试：新增 test_task_continue.py 11 个 + test_host_continue.py 2 个。

tests/test_host_continue.py

@@ -0,0 +1,86 @@
+"""旧任务接续 goal 模式：host.py goal-resume --goal-text。
+
+已终局的旧任务没有 goal 记录是正常情况，--goal-text 模式跳过
+状态与记录守卫，在旧线程上从第 1 轮开新目标循环（新语义：
+无验收、不传轮次时不限轮次，模型宣告完成才结束）。
+"""
+
+import json
+import os
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from unittest import mock
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO_ROOT))
+
+import host
+
+
+class FakeServer(object):
+    def __init__(self, text):
+        self.text = text
+        self.resumed = []
+
+    def initialize(self):
+        pass
+
+    def close(self):
+        pass
+
+    def resume_thread(self, thread_id):
+        self.resumed.append(thread_id)
+
+    def run_turn(self, thread_id, prompt, model=None, effort=None,
+                 sandbox=None, timeout=None):
+        return {"status": "completed", "text": self.text,
+                "turn_id": "u1"}
+
+
+class GoalResumeTextTest(unittest.TestCase):
+    def _run_main(self, task, goal_text):
+        with tempfile.TemporaryDirectory() as tmp:
+            state_path = os.path.join(tmp, "host-state.json")
+            cfg_path = os.path.join(tmp, "host-config.json")
+            with open(state_path, "w", encoding="utf-8") as f:
+                json.dump({"tasks": {"g": task}, "automations": []}, f)
+            with open(cfg_path, "w", encoding="utf-8") as f:
+                json.dump({}, f)
+            fake = FakeServer("done\n目标已达成")
+            argv = ["host.py", "--state", state_path,
+                    "--config", cfg_path,
+                    "goal-resume", "--task", "g"]
+            if goal_text is not None:
+                argv += ["--goal-text", goal_text]
+            with mock.patch.object(sys, "argv", argv):
+                with mock.patch.object(host, "Server",
+                                       lambda **kw: fake):
+                    host.main()
+            with open(state_path, encoding="utf-8") as f:
+                saved = json.load(f)["tasks"]["g"]
+            return saved, fake
+
+    def test_goal_text_init_on_completed_task(self):
+        task = {"name": "g", "thread_id": "x", "cwd": "/tmp",
+                "sandbox": None, "max_retries": 0, "retry_count": 0,
+                "turns": [], "status": "completed"}
+        saved, fake = self._run_main(task, "new goal")
+        self.assertEqual(saved["status"], "goal-met")
+        self.assertEqual(saved["goal"], "new goal")
+        self.assertEqual(saved["goal_rounds_done"], 1)
+        self.assertEqual(fake.resumed, ["x"])
+
+    def test_goal_text_refuses_task_without_thread(self):
+        task = {"name": "g", "cwd": "/tmp",
+                "sandbox": None, "max_retries": 0, "retry_count": 0,
+                "turns": [], "status": "completed"}
+        saved, fake = self._run_main(task, "new goal")
+        self.assertEqual(saved["status"], "completed")
+        self.assertEqual(fake.resumed, [])
+
+
+if __name__ == "__main__":
+    unittest.main()