refactor: address architect review findings (6 items)

R1: Extend @safe to catch ValueError->400, simplify routes_backtest
    (eliminated 4 copies of duplicated try/except)
R2: Consolidate PROVIDER constant into obb_utils.py (single source)
R3: Add days_ago() helper to obb_utils.py, replace 8+ duplications
R4: Extract Reddit/ApeWisdom into reddit_service.py from finnhub_service
R5: Fix missing top-level import asyncio in finnhub_service
R6: (deferred - sentiment logic extraction is a larger change)

All 561 tests passing.

routes_backtest.py

@@ -1,14 +1,11 @@
 """Routes for backtesting strategies."""
 
-import logging
-
-from fastapi import APIRouter, HTTPException
+from fastapi import APIRouter
 from pydantic import BaseModel, Field
 
 import backtest_service
 from models import ApiResponse
-
-logger = logging.getLogger(__name__)
+from route_utils import safe
 
 router = APIRouter(prefix="/api/v1/backtest", tags=["backtest"])
 
@@ -54,88 +51,56 @@ class MomentumRequest(BaseModel):
 
 
 @router.post("/sma-crossover", response_model=ApiResponse)
+@safe
 async def sma_crossover(req: SMARequest) -> ApiResponse:
     """SMA crossover strategy: buy when short SMA crosses above long SMA."""
-    try:
-        result = await backtest_service.backtest_sma_crossover(
-            req.symbol,
-            short_window=req.short_window,
-            long_window=req.long_window,
-            days=req.days,
-            initial_capital=req.initial_capital,
-        )
-        return ApiResponse(data=result)
-    except ValueError as exc:
-        logger.warning("SMA crossover backtest validation error: %s", exc)
-        raise HTTPException(status_code=400, detail=str(exc)) from exc
-    except Exception as exc:
-        logger.exception("SMA crossover backtest failed")
-        raise HTTPException(
-            status_code=502, detail="Data provider error. Check server logs."
-        ) from exc
+    result = await backtest_service.backtest_sma_crossover(
+        req.symbol,
+        short_window=req.short_window,
+        long_window=req.long_window,
+        days=req.days,
+        initial_capital=req.initial_capital,
+    )
+    return ApiResponse(data=result)
 
 
 @router.post("/rsi", response_model=ApiResponse)
+@safe
 async def rsi_strategy(req: RSIRequest) -> ApiResponse:
     """RSI strategy: buy when RSI < oversold, sell when RSI > overbought."""
-    try:
-        result = await backtest_service.backtest_rsi(
-            req.symbol,
-            period=req.period,
-            oversold=req.oversold,
-            overbought=req.overbought,
-            days=req.days,
-            initial_capital=req.initial_capital,
-        )
-        return ApiResponse(data=result)
-    except ValueError as exc:
-        logger.warning("RSI backtest validation error: %s", exc)
-        raise HTTPException(status_code=400, detail=str(exc)) from exc
-    except Exception as exc:
-        logger.exception("RSI backtest failed")
-        raise HTTPException(
-            status_code=502, detail="Data provider error. Check server logs."
-        ) from exc
+    result = await backtest_service.backtest_rsi(
+        req.symbol,
+        period=req.period,
+        oversold=req.oversold,
+        overbought=req.overbought,
+        days=req.days,
+        initial_capital=req.initial_capital,
+    )
+    return ApiResponse(data=result)
 
 
 @router.post("/buy-and-hold", response_model=ApiResponse)
+@safe
 async def buy_and_hold(req: BuyAndHoldRequest) -> ApiResponse:
     """Buy-and-hold benchmark: buy on day 1, hold through end of period."""
-    try:
-        result = await backtest_service.backtest_buy_and_hold(
-            req.symbol,
-            days=req.days,
-            initial_capital=req.initial_capital,
-        )
-        return ApiResponse(data=result)
-    except ValueError as exc:
-        logger.warning("Buy-and-hold backtest validation error: %s", exc)
-        raise HTTPException(status_code=400, detail=str(exc)) from exc
-    except Exception as exc:
-        logger.exception("Buy-and-hold backtest failed")
-        raise HTTPException(
-            status_code=502, detail="Data provider error. Check server logs."
-        ) from exc
+    result = await backtest_service.backtest_buy_and_hold(
+        req.symbol,
+        days=req.days,
+        initial_capital=req.initial_capital,
+    )
+    return ApiResponse(data=result)
 
 
 @router.post("/momentum", response_model=ApiResponse)
+@safe
 async def momentum_strategy(req: MomentumRequest) -> ApiResponse:
-    """Momentum strategy: every rebalance_days pick top_n symbols by lookback return."""
-    try:
-        result = await backtest_service.backtest_momentum(
-            symbols=req.symbols,
-            lookback=req.lookback,
-            top_n=req.top_n,
-            rebalance_days=req.rebalance_days,
-            days=req.days,
-            initial_capital=req.initial_capital,
-        )
-        return ApiResponse(data=result)
-    except ValueError as exc:
-        logger.warning("Momentum backtest validation error: %s", exc)
-        raise HTTPException(status_code=400, detail=str(exc)) from exc
-    except Exception as exc:
-        logger.exception("Momentum backtest failed")
-        raise HTTPException(
-            status_code=502, detail="Data provider error. Check server logs."
-        ) from exc
+    """Momentum strategy: every rebalance_days pick top_n by lookback return."""
+    result = await backtest_service.backtest_momentum(
+        symbols=req.symbols,
+        lookback=req.lookback,
+        top_n=req.top_n,
+        rebalance_days=req.rebalance_days,
+        days=req.days,
+        initial_capital=req.initial_capital,
+    )
+    return ApiResponse(data=result)