feat: add NFO scan after rescan and year caching

- Add nfo_scan_after_rescan config option (default: true)
- Implement year caching in AniworldLoader and EnhancedAniWorldLoader
- Make get_year abstract method in base provider
- Run NFO validation/creation after scheduled rescan completes
- Add _YearDict cache to avoid re-extracting year from HTML

tests/unit/test_enhanced_provider.py

@@ -45,6 +45,9 @@ class ConcreteEnhancedLoader(EnhancedAniWorldLoader):
     def get_title(self, key: str) -> str:
         return self.GetTitle(key)
 
+    def get_year(self, key: str) -> int | None:
+        return self.GetYear(key)
+
 
 @pytest.fixture
 def enhanced_loader():
@@ -969,6 +972,7 @@ class TestHlsUrlDetection:
     def test_voe_hls_pattern_extracts_hls_url(self):
         """HLS_PATTERN should extract HLS URL from VOE embedded player HTML."""
         import re
+
         from src.server.providers.streaming.voe import HLS_PATTERN
 
         html_with_hls = """
@@ -984,6 +988,7 @@ class TestHlsUrlDetection:
     def test_voe_hls_pattern_returns_none_when_no_hls(self):
         """HLS_PATTERN should return None when no HLS URL in HTML."""
         import re
+
         from src.server.providers.streaming.voe import HLS_PATTERN
 
         html_no_hls = """
@@ -997,6 +1002,7 @@ class TestHlsUrlDetection:
     def test_hls_url_detection_in_provider_flow(self, enhanced_loader, tmp_path):
         """Provider should detect and handle HLS URLs from VOE extractor."""
         import re
+
         from src.server.providers.streaming.voe import HLS_PATTERN
 
         # Simulate VOE returning an HLS URL (base64 encoded .m3u8)