fix: resolve compilation errors in tests by fixing type mismatches and imports

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

src/tests/db/meta_tests.rs

@@ -26,10 +26,10 @@ mod tests {
         
         // Try to get meta for non-existent item
         let item = crate::db::Item {
-            id: 999, // Non-existent item
+            id: Some(999), // Non-existent item
             ts: chrono::Utc::now(),
-            size: 0,
-            compression: crate::compression_engine::CompressionType::None,
+            size: Some(0),
+            compression: crate::compression_engine::CompressionType::None.to_string(),
         };
         
         let metas = db::get_item_meta(&conn, &item);