fix(pipeline): enforce group response rules after routing

Stop treating an explicit Pipeline route as permission to bypass group
response rules. Routed group messages must still satisfy the configured
mention or prefix matchers.

Preserve the bypass for verified interaction submissions that resume an
existing run. Cover ordinary messages, mentions, prefixes, and interaction
callbacks with regression tests.

src/langbot/pkg/pipeline/resprule/resprule.py

@@ -37,8 +37,10 @@ class GroupRespondRuleCheckStage(stage.PipelineStage):
         if query.launcher_type.value != 'group':  # 只处理群消息
             return entities.StageProcessResult(result_type=entities.ResultType.CONTINUE, new_query=query)
 
-        # 通过路由规则明确指定的流水线，跳过群响应规则检查
-        if query.variables and query.variables.get('_routed_by_rule', False):
+        # Verified interaction callbacks resume the original run without a new
+        # mention or prefix. Routing ordinary messages only selects a pipeline;
+        # it must not bypass that pipeline's group response rules.
+        if query.variables and query.variables.get('_interaction_submission'):
             return entities.StageProcessResult(result_type=entities.ResultType.CONTINUE, new_query=query)
 
         rules = query.pipeline_config['trigger']['group-respond-rules']