fix: IP校验改用endpoint级HTTPException替代Pydantic validator

model_validator/field_validator在自定义RequestValidationError handler下
无法正确序列化为JSON，导致500。改用endpoint级_validate_ip_list()辅助函数
抛HTTPException(400)，避免Pydantic→FastAPI序列化链路问题。

server/api/settings.py

@@ -14,7 +14,7 @@ import socket
 
 import bcrypt
 from fastapi import APIRouter, Depends, HTTPException, Request
-from pydantic import BaseModel, Field, field_validator
+from pydantic import BaseModel, Field
 
 from server.api.dependencies import get_db
 from server.api.auth_jwt import get_current_admin
@@ -93,6 +93,16 @@ async def _verify_reauth(db: AsyncSession, admin: Admin, password: str) -> None:
         raise HTTPException(status_code=400, detail="当前密码错误")
 
 
+def _validate_ip_list(ips: list[str]) -> None:
+    """Validate IP/CIDR/domain list. Raises 400 on invalid entry."""
+    for raw in ips:
+        ip = raw.strip()
+        if not ip:
+            continue
+        if not (_IP_RE.match(ip) or _DOMAIN_RE.match(ip)):
+            raise HTTPException(status_code=400, detail=f"无效的 IP/CIDR/域名: {ip}")
+
+
 # ── System Settings ──
 
 @router.get("/", response_model=list)
@@ -841,17 +851,6 @@ _DOMAIN_RE = re.compile(r"^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?(\.[a-zA-
 class IpAllowlistRequest(BaseModel):
     ips: list[str] = Field(..., min_length=1, max_length=100, description="IP or hostname list")
 
-    @field_validator("ips", mode="before")
-    @classmethod
-    def validate_ips(cls, v: list[str]) -> list[str]:
-        for raw in v:
-            ip = raw.strip()
-            if not ip:
-                continue
-            if not (_IP_RE.match(ip) or _DOMAIN_RE.match(ip)):
-                raise ValueError(f"无效的 IP/CIDR/域名: {ip}")
-        return v
-
 
 class SubscriptionParseRequest(BaseModel):
     url: str = Field(..., min_length=1, description="Proxy subscription URL to fetch and parse")
@@ -939,17 +938,6 @@ class IpAllowlistSaveRequest(BaseModel):
     subscription_url: Optional[str] = None   # None = don't change; "" = clear
     enabled: Optional[bool] = None           # None = don't change
 
-    @field_validator("manual_ips", mode="before")
-    @classmethod
-    def validate_manual_ips(cls, v: list[str]) -> list[str]:
-        for raw in v:
-            ip = raw.strip()
-            if not ip:
-                continue
-            if not (_IP_RE.match(ip) or _DOMAIN_RE.match(ip)):
-                raise ValueError(f"无效的 IP/CIDR/域名: {ip}")
-        return v
-
 
 @router.post("/ip-allowlist", response_model=dict)
 async def set_ip_allowlist(
@@ -960,6 +948,8 @@ async def set_ip_allowlist(
 ):
     """Save manual IPs, subscription URL, and/or enabled toggle."""
     from server.config import settings as _settings
+    if payload.manual_ips:
+        _validate_ip_list(payload.manual_ips)
 
     repo = SettingRepositoryImpl(db)
 
@@ -1046,6 +1036,7 @@ async def add_manual_ips(
 ):
     """Append IPs to the manual list and trigger allowlist rebuild."""
     from server.config import settings as _settings
+    _validate_ip_list(payload.ips)
 
     existing = [ip.strip() for ip in (_settings.LOGIN_MANUAL_IPS or "").split(",") if ip.strip()]
     new_ips = [ip.strip() for ip in payload.ips if ip.strip()]