test(ack): align allowedWorktrees deprecation tests with v0.19 contract

e4d4319 deprecated the allowedWorktrees whitelist (git worktree registry +
same common-dir checks replace it) but left 4 tests asserting the old
contract:

- test_ack_skill: template must NOT contain allowedWorktrees: anymore,
  only the deprecation comment
- test_ack_worker_profiles: legacy allowlist field is tolerated (no
  'requires at least one path'); receipt no longer validated against it
- test_ack_launch_worker: capture_worktree_identity dropped the
  allowlist arg; assert registered-worktree pass, symlink impostor and
  unregistered-rejection under the new signature

tests/test_ack_skill.py

@@ -153,9 +153,9 @@ class AckSkillContentTests(unittest.TestCase):
             REPO_ROOT / "skills" / "ack" / "templates" / "tasks.template.yaml"
         ).read_text(encoding="utf-8")
 
-        self.assertNotIn("repoPath:", template)
-        self.assertNotIn("devWorktree:", template)
-        self.assertIn("allowedWorktrees:", template)
+        # v0.19 起 allowedWorktrees 白名单废弃：模板只保留废弃说明注释，不再生成该字段
+        self.assertNotIn("allowedWorktrees:", template)
+        self.assertIn("allowedWorktrees", template)
         self.assertIn('knowledgeFile: "docs/ack/knowledge.yaml"', template)