treewide: complete book management interface

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: If5a21f16221f3c56a8008e139f93edc46a6a6964

crates/pinakes-core/src/metadata/mod.rs

@@ -9,6 +9,7 @@ use std::path::Path;
 
 use crate::error::Result;
 use crate::media_type::MediaType;
+use crate::model::ExtractedBookMetadata;
 
 #[derive(Debug, Clone, Default)]
 pub struct ExtractedMetadata {
@@ -20,6 +21,7 @@ pub struct ExtractedMetadata {
     pub duration_secs: Option<f64>,
     pub description: Option<String>,
     pub extra: HashMap<String, String>,
+    pub book_metadata: Option<ExtractedBookMetadata>,
 }
 
 pub trait MetadataExtractor: Send + Sync {