feat: Phase 1 - output quality verification + node-level auto-retry

- Add enterprise_review tool (35th builtin) for LLM-based quality assessment
- Add evaluator workflow node type for quality gating in DAG
- Add AgentRuntime built-in self-review with auto-correction loop
- Rewrite error_handler node from stub to real retry mechanism
- Add engine-level per-node retry with configurable max_retries/delay/on_exhausted
- Add AgentExtension model for extension tracking
- Enhance validation in agent_create_tool and tool_register_tool
- Update 全能助手 system prompt with self-evolution workflow
- Docs: 缺失能力.md and 解决缺失能力计划.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/agent_runtime/workflow_integration.py

@@ -97,6 +97,7 @@ async def run_agent_node(
         },
         budget=budget,
         user_id=user_id,
+        self_review_enabled=node_data.get("self_review_enabled", False),
     )
 
     # 4. 执行 Agent