docs: Add rustdoc comments to services/types.rs structs and methods

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/services/types.rs

@@ -4,12 +4,20 @@ use std::collections::HashMap;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ItemWithMeta {
+    /// The core item data.
     pub item: Item,
+    /// Associated tags.
     pub tags: Vec<Tag>,
+    /// Associated metadata.
     pub meta: Vec<Meta>,
 }
 
 impl ItemWithMeta {
+    /// Converts metadata to a HashMap for easy lookup.
+    ///
+    /// # Returns
+    ///
+    /// `HashMap<String, String>` - Metadata as key-value pairs.
     pub fn meta_as_map(&self) -> HashMap<String, String> {
         self.meta.iter().cloned().map(|m| (m.name, m.value)).collect()
     }
@@ -17,6 +25,8 @@ impl ItemWithMeta {
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ItemWithContent {
+    /// Item with associated metadata and tags.
     pub item_with_meta: ItemWithMeta,
+    /// The content bytes.
     pub content: Vec<u8>,
 }