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/domain/entities/share.rs

@@ -262,9 +262,9 @@ mod tests {
         assert_eq!(share.item_id(), "test_file_id");
         assert_eq!(*share.item_type(), ShareItemType::File);
         assert_eq!(share.created_by(), "user123");
-        assert_eq!(share.permissions().read(), true);
-        assert_eq!(share.permissions().write(), false);
-        assert_eq!(share.permissions().reshare(), false);
+        assert!(share.permissions().read());
+        assert!(!share.permissions().write());
+        assert!(!share.permissions().reshare());
         assert!(!share.has_password());
         assert!(share.expires_at().is_none());
         assert_eq!(share.access_count(), 0);