refactor: update meta plugins to use new trait interface

Co-authored-by: aider (openai/andrew/openrouter/mistralai/mistral-medium-3.1) <aider@aider.chat>

src/meta_plugin/binary.rs

@@ -82,40 +82,62 @@ impl MetaPlugin for BinaryMetaPlugin {
         true
     }
     
-    fn finalize(&mut self, conn: &Connection) -> Result<()> {
+    fn finalize(&mut self) -> Result<PluginResponse> {
+        let mut metadata = Vec::new();
+
         // Save the binary detection result when finalizing, if not already saved
-        self.save_metadata(conn)
+        if let Some(item_id) = self.item_id {
+            let is_binary_result = is_binary(&self.buffer);
+            let value = if is_binary_result { "true".to_string() } else { "false".to_string() };
+
+            if let Some(meta) = self.create_meta(item_id, "binary", value) {
+                metadata.push(meta);
+            }
+        }
+
+        Ok(PluginResponse {
+            metadata: Some(metadata),
+            is_finalized: true,
+        })
     }
 
-    fn update(&mut self, data: &[u8], conn: &Connection) {
-        // If we've already saved the metadata, no need to collect more data
-        if self.is_saved {
-            return;
-        }
-        
+    fn update(&mut self, data: &[u8]) -> Result<PluginResponse> {
         // Calculate how much data we can still accept
         let remaining_capacity = self.max_buffer_size.saturating_sub(self.buffer.len());
         if remaining_capacity > 0 {
             // Determine how much data to copy
             let bytes_to_take = std::cmp::min(data.len(), remaining_capacity);
-        
+
             // Add data to our buffer
             self.buffer.extend_from_slice(&data[..bytes_to_take]);
         }
-        
-        // If we've reached our buffer limit, save the metadata immediately
+
+        // If we've reached our buffer limit, return metadata
+        let mut metadata = Vec::new();
         if self.buffer.len() >= self.max_buffer_size {
-            let _ = self.save_metadata(conn);
+            if let Some(item_id) = self.item_id {
+                let is_binary_result = is_binary(&self.buffer);
+                let value = if is_binary_result { "true".to_string() } else { "false".to_string() };
+
+                if let Some(meta) = self.create_meta(item_id, "binary", value) {
+                    metadata.push(meta);
+                }
+            }
         }
+
+        Ok(PluginResponse {
+            metadata: if metadata.is_empty() { None } else { Some(metadata) },
+            is_finalized: !metadata.is_empty(),
+        })
     }
 
     fn meta_name(&self) -> String {
         self.meta_name.clone()
     }
     
-    fn initialize(&mut self, _conn: &Connection, item_id: i64) -> Result<()> {
+    fn initialize(&mut self, item_id: i64) -> Result<PluginResponse> {
         self.item_id = Some(item_id);
-        Ok(())
+        Ok(PluginResponse::default())
     }
     
     fn configure_options(&mut self, options: &std::collections::HashMap<String, serde_yaml::Value>) -> Result<()> {