fix: resolve clippy warnings and rustfmt issues for CI compliance

Fix all clippy lints (collapsible if, clone on Copy, needless borrow,
redundant bindings, unused params) and apply rustfmt across the codebase.
Update test mocks to match Uuid-based trait signatures.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/infrastructure/repositories/pg/folder_db_repository.rs

@@ -21,16 +21,7 @@ use crate::domain::services::path_service::StoragePath;
 type FolderRow = (String, String, String, Option<String>, Uuid, i64, i64);
 
 /// Type alias for paginated folder rows (includes total_count).
-type FolderRowPaginated = (
-    String,
-    String,
-    String,
-    Option<String>,
-    Uuid,
-    i64,
-    i64,
-    i64,
-);
+type FolderRowPaginated = (String, String, String, Option<String>, Uuid, i64, i64, i64);
 
 /// Type alias for folder rows with optional user_id.
 type FolderRowOptUser = (
@@ -108,14 +99,14 @@ impl FolderRepository for FolderDbRepository {
         // caller to have set up the home folder beforehand (done during user
         // registration).
         let user_id: Uuid = if let Some(ref pid) = parent_id {
-            sqlx::query_scalar::<_, Uuid>(
-                "SELECT user_id FROM storage.folders WHERE id = $1::uuid",
-            )
-            .bind(pid)
-            .fetch_optional(self.pool())
-            .await
-            .map_err(|e| DomainError::internal_error("FolderDb", format!("parent lookup: {e}")))?
-            .ok_or_else(|| DomainError::not_found("Folder", pid))?
+            sqlx::query_scalar::<_, Uuid>("SELECT user_id FROM storage.folders WHERE id = $1::uuid")
+                .bind(pid)
+                .fetch_optional(self.pool())
+                .await
+                .map_err(|e| {
+                    DomainError::internal_error("FolderDb", format!("parent lookup: {e}"))
+                })?
+                .ok_or_else(|| DomainError::not_found("Folder", pid))?
         } else {
             return Err(DomainError::internal_error(
                 "FolderDb",
@@ -647,15 +638,9 @@ impl FolderRepository for FolderDbRepository {
         .map_err(|e| DomainError::internal_error("FolderDb", format!("home folder: {e}")))?;
 
         match row {
-            Some((id, path, ca, ma)) => Self::row_to_folder(
-                id,
-                name.clone(),
-                path,
-                None,
-                Some(user_id),
-                ca,
-                ma,
-            ),
+            Some((id, path, ca, ma)) => {
+                Self::row_to_folder(id, name.clone(), path, None, Some(user_id), ca, ma)
+            }
             None => {
                 // Already exists — fetch it
                 let existing = sqlx::query_as::<_, (String, String, i64, i64)>(