refactor: apply clippy auto-fixes (162 warnings resolved)

- Fix needless borrows and references
- Collapse nested if statements
- Replace manual strip_prefix with str::strip_prefix()
- Remove redundant closures in map/unwrap_or_else
- Use Iterator::next_back() instead of rev().next()
- Simplify map_or patterns
- Use std::io::Error::other() instead of new(ErrorKind::Other, ..)
- Use div_ceil() instead of manual ceiling division
- Consolidate format! string arguments
- Various other idiomatic Rust improvements

39 files changed, 220 insertions(+), 320 deletions(-)

src/application/services/trash_service_test.rs

@@ -57,21 +57,19 @@ impl TrashRepository for MockTrashRepository {
 
     async fn restore_from_trash(&self, id: &Uuid, user_id: &Uuid) -> Result<()> {
         let mut items = self.trash_items.lock().unwrap();
-        if let Some(item) = items.get(id) {
-            if item.user_id() == *user_id {
+        if let Some(item) = items.get(id)
+            && item.user_id() == *user_id {
                 items.remove(id);
             }
-        }
         Ok(())
     }
 
     async fn delete_permanently(&self, id: &Uuid, user_id: &Uuid) -> Result<()> {
         let mut items = self.trash_items.lock().unwrap();
-        if let Some(item) = items.get(id) {
-            if item.user_id() == *user_id {
+        if let Some(item) = items.get(id)
+            && item.user_id() == *user_id {
                 items.remove(id);
             }
-        }
         Ok(())
     }