feat(pipeline): add adversarial loop schema models

Add ReviewIssue, ReviewFeedback, AdversarialState models and extend
PipelineStage with verifier, max_adversarial_rounds, feedback_mode,
and escalate_on_exhaust fields for Worker-Verifier adversarial loop.

src/agentkit/orchestrator/pipeline_schema.py

@@ -3,7 +3,7 @@
 from enum import Enum
 from typing import Any
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 from agentkit.orchestrator.retry import StepRetryPolicy
 
@@ -16,6 +16,31 @@ class StageStatus(str, Enum):
     SKIPPED = "skipped"
 
 
+class ReviewIssue(BaseModel):
+    """单条审查问题"""
+    severity: str = Field(description="问题严重程度: critical/major/minor")
+    category: str = Field(description="问题类别: logic_error/security/style/test_failure/architecture")
+    description: str = Field(description="问题描述")
+    location: str | None = Field(default=None, description="文件路径/行号")
+    suggestion: str | None = Field(default=None, description="修复建议")
+
+
+class ReviewFeedback(BaseModel):
+    """Verifier 返回的结构化审查反馈"""
+    passed: bool = Field(description="是否通过审查")
+    issues: list[ReviewIssue] = Field(default_factory=list, description="问题列表")
+    summary: str = Field(description="自然语言审查报告")
+    score: float = Field(description="质量评分 (0-1)")
+
+
+class AdversarialState(BaseModel):
+    """对抗轮次状态追踪"""
+    current_round: int = Field(default=0, description="当前对抗轮次")
+    max_rounds: int = Field(default=3, description="最大对抗轮次")
+    feedback_history: list[ReviewFeedback] = Field(default_factory=list, description="反馈历史")
+    last_feedback: ReviewFeedback | None = Field(default=None, description="最后一次反馈")
+
+
 class PipelineStage(BaseModel):
     name: str
     agent: str
@@ -29,6 +54,12 @@ class PipelineStage(BaseModel):
     condition: str | None = None
     retry_policy: StepRetryPolicy | None = None
     compensate: str | None = None
+    
+    # 对抗闭环相关字段
+    verifier: str | None = Field(default=None, description="Verifier Agent 名称，配置后启用对抗模式")
+    max_adversarial_rounds: int = Field(default=3, description="最大对抗轮次")
+    feedback_mode: str = Field(default="structured+natural", description="反馈模式: structured+natural / structured / natural")
+    escalate_on_exhaust: str | None = Field(default=None, description="对抗轮次耗尽后的升级目标")
 
     model_config = {"arbitrary_types_allowed": True}