Add unit tests for DingTalk, Lark, WeComBot, and Dify service API runners

- Implement tests for DingTalk adapter helper functions including form content cleaning, input extraction, and completed input lines.
- Create unit tests for Lark adapter helper functions focusing on input extraction and completed input lines.
- Add tests for WeComBot template card functionalities, including event extraction and payload building for human input.
- Enhance Dify service API runner tests to cover human input forms, including input collection, action handling, and form snapshot extraction.

tests/unit_tests/platform/test_dingtalk_api.py

@@ -0,0 +1,42 @@
+"""Tests for DingTalk API payload helpers."""
+
+import json
+
+from langbot.libs.dingtalk_api.api import _stringify_card_param_map
+
+
+def test_dingtalk_card_param_map_stringifies_select_component_arrays():
+    params = _stringify_card_param_map(
+        {
+            'content': 'Pick one',
+            'btns': json.dumps([{'text': 'OK'}], ensure_ascii=False),
+            'select_options': ['A', 'B'],
+            'index_o': [
+                {
+                    'value': 'A',
+                    'text': {'zh_CN': 'A', 'en_US': 'A'},
+                }
+            ],
+            'test_index': [
+                {
+                    'value': 'A',
+                    'text': {'zh_CN': 'A', 'en_US': 'A'},
+                }
+            ],
+            'select_index': -1,
+        }
+    )
+
+    assert params['content'] == 'Pick one'
+    assert params['btns'] == '[{"text": "OK"}]'
+    assert params['select_options'] == '["A", "B"]'
+    assert json.loads(params['index_o'])[0]['value'] == 'A'
+    assert json.loads(params['test_index'])[0]['value'] == 'A'
+    assert params['select_index'] == '-1'
+
+
+def test_dingtalk_card_param_map_stringifies_unregistered_structures():
+    params = _stringify_card_param_map({'other': ['A'], 'empty': None})
+
+    assert params['other'] == '["A"]'
+    assert params['empty'] == ''