Apply clippy fixes for code quality

Clippy Fixes Applied:
- Removed unused imports
- Fixed manual implementation of .is_multiple_of()
- Fixed unnecessary_sort_by suggestions
- Added missing Ipv4Addr imports

Files Modified:
- forward_acl.rs: Add Ipv4Addr import
- known_hosts.rs: Add Ipv4Addr import
- Various files: Remove unused imports

Build: ✅ markbase-core
Tests: 495 passed

markbase-core/src/s3.rs

@@ -87,7 +87,7 @@ pub async fn list_objects(
 
 pub async fn get_object(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     headers: HeaderMap,
 ) -> impl IntoResponse {
     println!("S3 GET Object: bucket={}, key={}", bucket, key);
@@ -174,7 +174,7 @@ pub async fn get_object(
 
 pub async fn put_object(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     headers: HeaderMap,
     body: Body,
 ) -> impl IntoResponse {
@@ -378,7 +378,7 @@ pub async fn generate_s3_key(State(state): State<crate::server::AppState>) -> im
 
 pub async fn delete_object(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     headers: HeaderMap,
 ) -> impl IntoResponse {
     println!("S3 DELETE Object: bucket={}, key={}", bucket, key);
@@ -606,7 +606,7 @@ static MULTIPART_UPLOADS: once_cell::sync::Lazy<Arc<RwLock<HashMap<String, Multi
 
 pub async fn initiate_multipart_upload(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     headers: HeaderMap,
 ) -> impl IntoResponse {
     // Authentication check
@@ -641,7 +641,7 @@ pub async fn initiate_multipart_upload(
 
 pub async fn upload_part(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     query: axum::extract::Query<UploadPartQuery>,
     headers: HeaderMap,
     body: Body,
@@ -732,7 +732,7 @@ pub struct UploadPartQuery {
 
 pub async fn complete_multipart_upload(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     query: axum::extract::Query<CompleteMultipartQuery>,
     headers: HeaderMap,
     body: Body,
@@ -835,7 +835,7 @@ pub struct CompleteMultipartQuery {
 
 pub async fn abort_multipart_upload(
     Path((bucket, key)): Path<(String, String)>,
-    State(state): State<crate::server::AppState>,
+    State(_state): State<crate::server::AppState>,
     query: axum::extract::Query<AbortMultipartQuery>,
     headers: HeaderMap,
 ) -> impl IntoResponse {