feat: support wecom channel (#1390)

* feat: support wecom channel

* fix: sending file to client

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* test: add unit tests for wecom channel

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* docs: add example configs and setup docs

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* revert pypi default index setting

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* revert: keeping codes in harness untouched

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* fix: format issue

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

* fix: resolve Copilot comments

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>

---------

Signed-off-by: fengxusong <7008971+fengxsong@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

config.example.yaml

@@ -232,7 +232,6 @@ models:
   #   supports_vision: true
   #   supports_thinking: true
 
-  
   # Example: OpenRouter (OpenAI-compatible)
   # OpenRouter models use the same ChatOpenAI + base_url pattern as other OpenAI-compatible gateways.
   # - name: openrouter-gemini-2.5-flash
@@ -687,6 +686,10 @@ checkpointer:
 #           context:
 #             thinking_enabled: true
 #             subagent_enabled: true
+#   wecom:
+#     enabled: false
+#     bot_id: $WECOM_BOT_ID
+#     bot_secret: $WECOM_BOT_SECRET
 
 # ============================================================================
 # Guardrails Configuration