Apply clippy suggestions

- Use `BTreeMap::entry` API in `update_item`
- Replace `or_insert_with(Vec::new)` with `or_default`
- Iterate over map values instead of key-value pairs
- Use `std::io::Error::other` for custom errors
- Simplify filter logic with direct predicate
- Replace manual `Into` implementation with `From`
- Remove unnecessary explicit returns

1 files changed, 3 insertions, 3 deletions

diff --git a/src/who.rs b/src/who.rs
index 32f536b..8e16765 100644
--- a/src/who.rs
+++ b/src/who.rs
@@ -33,9 +33,9 @@ impl From<&str> for Who {
     }
 }
 
-impl Into<String> for Who {
-    fn into(self) -> String {
-        self.name
+impl From<Who> for String {
+    fn from(val: Who) -> Self {
+        val.name
     }
 }