feat: add missing database functions and fix tool errors

Co-authored-by: aider (openai/andrew/openrouter/anthropic/claude-sonnet-4) <aider@aider.chat>

src/db.rs

@@ -87,6 +87,37 @@ pub fn insert_item(conn: &Connection, item: Item) -> Result<i64> {
     Ok(conn.last_insert_rowid())
 }
 
+pub fn create_item(conn: &Connection, compression_type: crate::compression_engine::CompressionType) -> Result<Item> {
+    let item = Item {
+        id: None,
+        ts: chrono::Utc::now(),
+        size: None,
+        compression: compression_type.to_string(),
+    };
+    let item_id = insert_item(conn, item.clone())?;
+    Ok(Item {
+        id: Some(item_id),
+        ..item
+    })
+}
+
+pub fn add_tag(conn: &Connection, item_id: i64, tag_name: &str) -> Result<()> {
+    let tag = Tag {
+        id: item_id,
+        name: tag_name.to_string(),
+    };
+    insert_tag(conn, tag)
+}
+
+pub fn add_meta(conn: &Connection, item_id: i64, name: &str, value: &str) -> Result<()> {
+    let meta = Meta {
+        id: item_id,
+        name: name.to_string(),
+        value: value.to_string(),
+    };
+    store_meta(conn, meta)
+}
+
 pub fn update_item(conn: &Connection, item: Item) -> Result<()> {
     debug!("DB: Updating item: {:?}", item);
     conn.execute(