fix(config): align default filter regex from \d+-\d to \d+-\d+

The per-bangumi default in Bangumi model already uses \d+-\d+ to filter
batch/collection torrents (e.g. '01-13'). The global RSSParser default
was inconsistently using \d+-\d (one fewer +), which has subtly different
matching behaviour.

Align both defaults to \d+-\d+ for consistency.

Author: HuajunGao

backend/src/module/models/config.py

@@ -51,7 +51,7 @@ class RSSParser(BaseModel):
     """RSS feed parsing settings."""
 
     enable: bool = Field(True, description="Enable RSS parser")
-    filter: list[str] = Field(["720", r"\d+-\d"], description="Filter")
+    filter: list[str] = Field(["720", r"\d+-\d+"], description="Filter")
     language: str = "zh"