fix search/filter bugs in game and TV libraries

- Game series: filter now checks child games for both search and tag matches instead of always passing series through
- TV episodes: tag selector no longer closes after picking a tag
- TV episodes: filter panel now filters episodes within a season view
- TV series list: series now appear when any of their episodes match the active tag filter (via new /api/tv/series-episode-tags endpoint backed by media_items)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/tags.ts

@@ -215,6 +215,42 @@ export function getTagAssignmentsForLibrary(libraryId: string): Record<string, s
   return result
 }
 
+// Returns seriesId -> tagIds[] aggregated from all episodes in each series.
+// Requires media_items to be populated by the scanner. Returns {} if not yet scanned.
+export function getSeriesEpisodeTagMap(libraryId: string): Record<string, string[]> {
+  const db = getDb()
+  const prefix = `${libraryId}:tv_episode:`
+  const episodes = db
+    .prepare('SELECT item_key FROM media_items WHERE library_id = ? AND item_type = ?')
+    .all(libraryId, 'tv_episode') as { item_key: string }[]
+  if (episodes.length === 0) return {}
+
+  const tagRows = db
+    .prepare('SELECT media_key, tag_id FROM media_tags WHERE media_key LIKE ?')
+    .all(`${libraryId}:%`) as { media_key: string; tag_id: string }[]
+  const tagsByMediaKey: Record<string, string[]> = {}
+  for (const row of tagRows) {
+    ;(tagsByMediaKey[row.media_key] ??= []).push(row.tag_id)
+  }
+
+  const result: Record<string, string[]> = {}
+  for (const { item_key } of episodes) {
+    if (!item_key.startsWith(prefix)) continue
+    // item_key: "libraryId:tv_episode:seriesId:seasonId:episodeId"
+    const parts = item_key.split(':')
+    if (parts.length < 5) continue
+    const seriesId = parts[2]
+    const episodeId = parts[parts.length - 1]
+    const episodeTags = tagsByMediaKey[`${libraryId}:${episodeId}`]
+    if (!episodeTags) continue
+    const seriesTags = (result[seriesId] ??= [])
+    for (const tagId of episodeTags) {
+      if (!seriesTags.includes(tagId)) seriesTags.push(tagId)
+    }
+  }
+  return result
+}
+
 export function removeAllAssignmentsForLibrary(libraryId: string): void {
   const db = getDb()
   db.prepare("DELETE FROM media_tags WHERE media_key LIKE ?").run(`${libraryId}:%`)