Add library_type_name column to media_items with auto-population trigger

- Add library_type_name VARCHAR(50) column to media_items table in schema.sql
- Create PostgreSQL trigger 'set_library_type_name_on_insert' that automatically
  populates library_type_name by joining libraries table with library_types on insert
- Add library_type_name parameter to CreateMediaItem SQL query
- Update Go models (models.go) to include LibraryTypeName field
- Add UpdateMediaItemChapterMetadata query method to querier.go
- Regenerate queries.sql.go with sqlc

This allows media items to store their library type (e.g., 'Books', 'Comics', 'Manga')
at the database level, enabling filtering and display without needing additional joins.

internal/database/models.go

@@ -279,6 +279,7 @@ type MediaItems struct {
 	// Summary from ComicInfo.xml (may be merged with description from Calibre)
 	Summary            pgtype.Text `db:"summary" json:"summary"`
 	ChapterMetadata    []byte      `db:"chapter_metadata" json:"chapter_metadata"`
+	LibraryTypeName    pgtype.Text `db:"library_type_name" json:"library_type_name"`
 	TagsSearch         []string    `db:"tags_search" json:"tags_search"`
 	ContributorsSearch []string    `db:"contributors_search" json:"contributors_search"`
 	FileSha256         pgtype.Text `db:"file_sha256" json:"file_sha256"`