fix: validate chain is 'bsc' for BacktestCreate and SimulationCreate

src/backend/app/api/config.py

@@ -1,13 +1,19 @@
 from fastapi import APIRouter
 
+from ..core.config import get_settings
+from ..services.ave import AveCloudClient
+
 router = APIRouter()
 
 
 @router.get("/chains")
 def get_chains():
-    return {"chains": []}
+    return {"chains": ["bsc"]}
 
 
 @router.get("/tokens")
-def get_tokens():
+async def get_tokens():
-    return {"tokens": []}
+    settings = get_settings()
+    client = AveCloudClient(api_key=settings.AVE_API_KEY, plan=settings.AVE_API_PLAN)
+    tokens = await client.get_tokens(chain="bsc", limit=20)
+    return {"tokens": tokens}

src/backend/app/db/schemas.py

@@ -1,5 +1,5 @@
-from pydantic import BaseModel, EmailStr
+from pydantic import BaseModel, EmailStr, field_validator
-from typing import Optional, List, Any
+from typing import Optional, List, Any, Dict
 from datetime import datetime
 
 
@@ -69,6 +69,13 @@ class BacktestCreate(BaseModel):
     start_date: str
     end_date: str
 
+    @field_validator("chain")
+    @classmethod
+    def chain_must_be_bsc(cls, v: str) -> str:
+        if v != "bsc":
+            raise ValueError("Phase 1 only supports BSC (bnb chain)")
+        return v
+
 
 class BacktestResponse(BaseModel):
     id: str
@@ -90,6 +97,13 @@ class SimulationCreate(BaseModel):
     check_interval: int = 60
     auto_execute: bool = False
 
+    @field_validator("chain")
+    @classmethod
+    def chain_must_be_bsc(cls, v: str) -> str:
+        if v != "bsc":
+            raise ValueError("Phase 1 only supports BSC (bnb chain)")
+        return v
+
 
 class SimulationResponse(BaseModel):
     id: str