feat(failover): 支持 Provider 级别故障转移规则，默认全部转移策略

- 新增 failover_rules 配置：支持 success_failover_patterns（成功响应匹配时转移）
  和 error_stop_patterns（错误响应匹配时终止），支持按 status_code 过滤
- 修改默认转移策略：ErrorClassifier 不再返回 RAISE，所有错误默认继续转移
- TaskService 中客户端错误不再直接抛出，改为 break 继续尝试下一个候选
- 修复 proxy tunnel 连接/断连竞态：引入 per-node 锁和事件时间戳排序
- 优化 ProxyNode 状态判定：OFFLINE 统一由心跳超时判定，兼容多 worker 场景
- has_tunnel 改为纯检查方法，避免在 finally 块中误清理新注册连接
- Redis stream NOGROUP 异常自愈处理
- OAuthAccountDialog 输入框焦点样式补全

src/models/admin_requests.py

@@ -80,6 +80,53 @@ class ProxyConfig(BaseModel):
         return self
 
 
+class FailoverRuleItem(BaseModel):
+    """故障转移规则条目"""
+
+    pattern: str = Field(..., min_length=1, max_length=500, description="正则表达式")
+    description: str = Field("", max_length=200, description="规则描述")
+    status_codes: list[int] | None = Field(
+        default=None,
+        description="HTTP 状态码列表（可选，为空时匹配所有状态码）",
+    )
+
+    @field_validator("pattern")
+    @classmethod
+    def validate_pattern(cls, v: str) -> str:
+        """验证正则表达式语法"""
+        import re as _re
+
+        try:
+            _re.compile(v)
+        except _re.error as e:
+            raise ValueError(f"无效的正则表达式: {e}")
+        return v
+
+    @field_validator("status_codes")
+    @classmethod
+    def validate_status_codes(cls, v: list[int] | None) -> list[int] | None:
+        """验证 HTTP 状态码"""
+        if v is None:
+            return v
+        for code in v:
+            if not (100 <= code <= 599):
+                raise ValueError(f"无效的 HTTP 状态码: {code}")
+        return v
+
+
+class FailoverRulesConfig(BaseModel):
+    """故障转移规则配置"""
+
+    success_failover_patterns: list[FailoverRuleItem] = Field(
+        default_factory=list,
+        description="成功响应转移规则: HTTP 200 但响应体匹配正则时触发转移",
+    )
+    error_stop_patterns: list[FailoverRuleItem] = Field(
+        default_factory=list,
+        description="错误终止规则: HTTP 非 200 且响应体匹配正则时停止转移",
+    )
+
+
 class PoolAdvancedConfig(BaseModel):
     """通用号池配置（适用于所有 Provider 类型）。"""
 
@@ -247,6 +294,7 @@ class CreateProviderRequest(BaseModel):
     claude_code_advanced: ClaudeCodeAdvancedConfig | None = Field(
         None, description="Claude Code 特有配置"
     )
+    failover_rules: FailoverRulesConfig | None = Field(None, description="故障转移规则配置")
     config: dict[str, Any] | None = Field(None, description="其他配置")
 
     @field_validator("provider_type")
@@ -356,6 +404,7 @@ class UpdateProviderRequest(BaseModel):
     claude_code_advanced: ClaudeCodeAdvancedConfig | None = Field(
         None, description="Claude Code 特有配置"
     )
+    failover_rules: FailoverRulesConfig | None = Field(None, description="故障转移规则配置")
     config: dict[str, Any] | None = None
 
     # 复用相同的验证器

src/models/endpoint_models.py

@@ -10,7 +10,12 @@ from typing import Any, Literal
 
 from pydantic import BaseModel, ConfigDict, Field, field_validator
 
-from src.models.admin_requests import ClaudeCodeAdvancedConfig, PoolAdvancedConfig, ProxyConfig
+from src.models.admin_requests import (
+    ClaudeCodeAdvancedConfig,
+    FailoverRulesConfig,
+    PoolAdvancedConfig,
+    ProxyConfig,
+)
 
 # ========== Header Rule 类型定义 ==========
 # 请求头规则支持三种操作：
@@ -938,6 +943,7 @@ class ProviderUpdateRequest(BaseModel):
         None, description="Claude Code 高级配置"
     )
     pool_advanced: PoolAdvancedConfig | None = Field(None, description="通用号池配置")
+    failover_rules: FailoverRulesConfig | None = Field(None, description="故障转移规则配置")
 
 
 class ProviderWithEndpointsSummary(BaseModel):
@@ -982,6 +988,7 @@ class ProviderWithEndpointsSummary(BaseModel):
         default=None, description="Claude Code 高级配置"
     )
     pool_advanced: PoolAdvancedConfig | None = Field(default=None, description="通用号池配置")
+    failover_rules: FailoverRulesConfig | None = Field(default=None, description="故障转移规则配置")
 
     # Endpoint 统计
     total_endpoints: int = Field(default=0, description="总 Endpoint 数量")