feat: add social media sentiment endpoints

- /stock/{symbol}/social-sentiment -- Finnhub Reddit+Twitter sentiment
  (requires premium, gracefully degrades)
- /stock/{symbol}/reddit-sentiment -- Reddit WSB/stocks/investing
  mentions, upvotes, rank via ApeWisdom (free, no key)
- /discover/reddit-trending -- Top 25 trending stocks on Reddit
  (free, no key)

ApeWisdom provides real-time Reddit data without API key.
Finnhub social-sentiment requires premium plan but endpoint
responds gracefully with premium_required flag.

routes_sentiment.py

@@ -101,3 +101,33 @@ async def stock_upgrades(symbol: str = Path(..., min_length=1, max_length=20)):
     symbol = validate_symbol(symbol)
     data = await openbb_service.get_upgrades_downgrades(symbol)
     return ApiResponse(data=data)
+
+
+@router.get("/stock/{symbol}/social-sentiment", response_model=ApiResponse)
+@safe
+async def stock_social_sentiment(
+    symbol: str = Path(..., min_length=1, max_length=20),
+):
+    """Social media sentiment from Reddit and Twitter (Finnhub)."""
+    symbol = validate_symbol(symbol)
+    data = await finnhub_service.get_social_sentiment(symbol)
+    return ApiResponse(data=data)
+
+
+@router.get("/stock/{symbol}/reddit-sentiment", response_model=ApiResponse)
+@safe
+async def stock_reddit_sentiment(
+    symbol: str = Path(..., min_length=1, max_length=20),
+):
+    """Reddit sentiment: mentions, upvotes, rank on WSB/stocks/investing (free, no key)."""
+    symbol = validate_symbol(symbol)
+    data = await finnhub_service.get_reddit_sentiment(symbol)
+    return ApiResponse(data=data)
+
+
+@router.get("/discover/reddit-trending", response_model=ApiResponse)
+@safe
+async def reddit_trending():
+    """Top 25 trending stocks on Reddit (WSB, r/stocks, r/investing). Free, no key."""
+    data = await finnhub_service.get_reddit_trending()
+    return ApiResponse(data=data)