test: mark live yfinance network tests as integration

TestYfinanceIndustryPerformance, TestRouteToVendorFallback, and TestFallbackRouting
all make live HTTP calls to yfinance (yfinance.Sector / market movers). Mark them
@pytest.mark.integration so they're skipped in standard offline runs.

https://claude.ai/code/session_01TuPpssTo83whKkNgSu57HH

tests/test_scanner_fallback.py

@@ -54,6 +54,7 @@ class TestYfinanceSectorPerformance:
             assert "Error:" not in day_pct, f"Error in 1-day for {cols[0]}: {day_pct}"
 
 
+@pytest.mark.integration
 class TestYfinanceIndustryPerformance:
     """Verify yfinance industry performance uses index for ticker symbols."""
 
@@ -94,6 +95,7 @@ class TestAlphaVantageFailoverRaise:
                 get_industry_performance_alpha_vantage("technology")
 
 
+@pytest.mark.integration
 class TestRouteToVendorFallback:
     """Verify route_to_vendor falls back from AV to yfinance."""
 

tests/test_scanner_routing.py

@@ -50,6 +50,7 @@ class TestScannerRouting:
         assert "News" in result
 
 
+@pytest.mark.integration
 class TestFallbackRouting:
 
     def setup_method(self):