feat: update media filter to support multiple series names and enhance library item fetching

k-tv-backend/domain/src/value_objects.rs

@@ -606,9 +606,11 @@ pub struct MediaFilter {
     /// Abstract groupings interpreted by each provider (Jellyfin library, Plex section,
     /// filesystem path, etc.). An empty list means "all available content".
     pub collections: Vec<String>,
-    /// Filter by TV series name. Use with `content_type: Episode` and
-    /// `strategy: Sequential` for ordered series playback (e.g. "iCarly").
-    pub series_name: Option<String>,
+    /// Filter to one or more TV series by name. Use with `content_type: Episode`.
+    /// With `Sequential` strategy each series plays in chronological order.
+    /// Multiple series are OR-combined: any episode from any listed show is eligible.
+    #[serde(default)]
+    pub series_names: Vec<String>,
     /// Free-text search term. Intended for library browsing; typically omitted
     /// during schedule generation.
     pub search_term: Option<String>,