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/dtos/pagination.rs

@@ -97,7 +97,7 @@ impl<T> PaginatedResponseDto<T> {
         let total_pages = if total_items == 0 {
             0
         } else {
-            (total_items + page_size - 1) / page_size
+            total_items.div_ceil(page_size)
         };
         
         let pagination = PaginationDto {