Add year support to anime folder names

- Add year property to Serie entity with name_with_year
- Add year column to AnimeSeries database model
- Add get_year() method to AniworldLoader provider
- Extract year from folder names before fetching from API
- Update SerieScanner to populate year during rescan
- Update add_series endpoint to fetch and store year
- Optimize: check folder name for year before API call

src/server/database/models.py

@@ -73,6 +73,10 @@ class AnimeSeries(Base, TimestampMixin):
         String(1000), nullable=False,
         doc="Filesystem folder name - METADATA ONLY, not for lookups"
     )
+    year: Mapped[Optional[int]] = mapped_column(
+        Integer, nullable=True,
+        doc="Release year of the series"
+    )
     
     # Relationships
     episodes: Mapped[List["Episode"]] = relationship(