fix: salvage follow-ups for Feishu QR onboarding (#7706)

- Remove duplicate _setup_feishu() definition (old 3-line version left
  behind by cherry-pick — Python picked the new one but dead code
  remained)
- Remove misleading 'Disable direct messages' DM option — the Feishu
  adapter has no DM policy mechanism, so 'disable' produced identical
  env vars to 'pairing'. Users who chose 'disable' would still see
  pairing prompts. Reduced to 3 options: pairing, allow-all, allowlist.
- Fix test_probe_returns_bot_info_on_success and
  test_probe_returns_none_on_failure: patch FEISHU_AVAILABLE=True so
  probe_bot() takes the SDK path when lark_oapi is not installed

tests/gateway/test_feishu_onboard.py

@@ -248,6 +248,7 @@ class TestRenderQr:
 class TestProbeBot:
     """Tests for bot connectivity verification."""
 
+    @patch("gateway.platforms.feishu.FEISHU_AVAILABLE", True)
     def test_probe_returns_bot_info_on_success(self):
         from gateway.platforms.feishu import probe_bot
 
@@ -259,6 +260,7 @@ class TestProbeBot:
         assert result["bot_name"] == "TestBot"
         assert result["bot_open_id"] == "ou_bot123"
 
+    @patch("gateway.platforms.feishu.FEISHU_AVAILABLE", True)
     def test_probe_returns_none_on_failure(self):
         from gateway.platforms.feishu import probe_bot
 

tests/gateway/test_setup_feishu.py

@@ -181,11 +181,6 @@ class TestSetupFeishuDmPolicy:
         env = self._run_with_dm_choice(2, prompt_responses=["ou_owner", ""])
         assert env["FEISHU_ALLOWED_USERS"] == "ou_owner"
 
-    def test_disabled_sets_feishu_allow_all_false(self):
-        env = self._run_with_dm_choice(3)
-        assert env["FEISHU_ALLOW_ALL_USERS"] == "false"
-        assert env["FEISHU_ALLOWED_USERS"] == ""
-        assert "GATEWAY_ALLOW_ALL_USERS" not in env
 
 
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