fix: resolve all clippy warnings and enforce cargo fmt

- display_helpers: convert module doc-comments to regular comments,
  merge identical text/markdown + text/ branches
- search_service: replace needless range loops with slice-based pagination
- folder_repository, folder_db_repository: collapse nested if statements
- favorites_pg_repository: remove unnecessary borrow on generic arg
- file_blob_read_repository: collapse 6 nested if-let blocks
- file_blob_write_repository: collapse nested if for dedup ref decrement
- chunked_upload_service: use div_ceil(), collapse 2 nested if blocks
- folder_handler: collapse nested if-let for owner check
- webdav_handler: replace 7x io::Error::new(ErrorKind::Other, ..) with
  io::Error::other(..)
- cargo fmt applied to all files

Passes: cargo clippy --all-targets --all-features -- -D warnings

src/common/config.rs

@@ -209,9 +209,9 @@ impl Default for StorageConfig {
     fn default() -> Self {
         Self {
             root_dir: "storage".to_string(),
-            chunk_size: 1024 * 1024,               // 1 MB
-            parallel_threshold: 100 * 1024 * 1024, // 100 MB
-            trash_retention_days: 30,              // 30 days
+            chunk_size: 1024 * 1024,                  // 1 MB
+            parallel_threshold: 100 * 1024 * 1024,    // 100 MB
+            trash_retention_days: 30,                 // 30 days
             max_upload_size: 10 * 1024 * 1024 * 1024, // 10 GB
         }
     }
@@ -615,8 +615,7 @@ impl AppConfig {
         }
 
         // Storage limits
-        if let Ok(max_upload) = env::var("OXICLOUD_MAX_UPLOAD_SIZE")
-            .map(|v| v.parse::<usize>())
+        if let Ok(max_upload) = env::var("OXICLOUD_MAX_UPLOAD_SIZE").map(|v| v.parse::<usize>())
             && let Ok(val) = max_upload
         {
             config.storage.max_upload_size = val;

src/common/di.rs

@@ -36,10 +36,10 @@ use crate::application::services::{
 use crate::common::config::AppConfig;
 use crate::common::errors::DomainError;
 use crate::domain::services::i18n_service::I18nService;
+use crate::infrastructure::repositories::pg::SharePgRepository;
 use crate::infrastructure::repositories::pg::{
     FileBlobReadRepository, FileBlobWriteRepository, FolderDbRepository, TrashDbRepository,
 };
-use crate::infrastructure::repositories::pg::SharePgRepository;
 use crate::infrastructure::services::file_content_cache::{
     FileContentCache, FileContentCacheConfig,
 };
@@ -334,11 +334,13 @@ impl AppServiceFactory {
 
         // Build a password hasher for share password verification
         let password_hasher: Arc<dyn crate::application::ports::auth_ports::PasswordHasherPort> =
-            Arc::new(crate::infrastructure::services::password_hasher::Argon2PasswordHasher::new(
-                self.config.auth.hash_memory_cost,
-                self.config.auth.hash_time_cost,
-                self.config.auth.hash_parallelism,
-            ));
+            Arc::new(
+                crate::infrastructure::services::password_hasher::Argon2PasswordHasher::new(
+                    self.config.auth.hash_memory_cost,
+                    self.config.auth.hash_time_cost,
+                    self.config.auth.hash_parallelism,
+                ),
+            );
 
         let service = Arc::new(ShareService::new(
             Arc::new(self.config.clone()),
@@ -470,7 +472,8 @@ impl AppServiceFactory {
             recent_service = Some(recent.clone());
             apps.recent_service = Some(recent);
 
-            storage_usage_service = Some(self.create_storage_usage_service(&repos, &pool, &maintenance_pool));
+            storage_usage_service =
+                Some(self.create_storage_usage_service(&repos, &pool, &maintenance_pool));
 
             // Auth services
             if self.config.features.enable_auth {

src/common/stubs.rs

@@ -621,7 +621,11 @@ pub struct StubSearchUseCase;
 
 #[async_trait]
 impl SearchUseCase for StubSearchUseCase {
-    async fn search(&self, _criteria: SearchCriteriaDto, _user_id: &str) -> Result<SearchResultsDto, DomainError> {
+    async fn search(
+        &self,
+        _criteria: SearchCriteriaDto,
+        _user_id: &str,
+    ) -> Result<SearchResultsDto, DomainError> {
         Ok(SearchResultsDto::empty())
     }
 
@@ -794,7 +798,14 @@ impl ContentCachePort for StubContentCachePort {
         None
     }
 
-    async fn put(&self, _file_id: String, _content: Bytes, _etag: Arc<str>, _content_type: Arc<str>) {}
+    async fn put(
+        &self,
+        _file_id: String,
+        _content: Bytes,
+        _etag: Arc<str>,
+        _content_type: Arc<str>,
+    ) {
+    }
 
     async fn invalidate(&self, _file_id: &str) {}