perf: make StoragePath::join and File builders consume self to avoid clones

StoragePath::join deep-cloned the whole Vec<String> (every segment String)
just to append one element. Take self by value and push in place. All callers
pass owned values except PathService::create_file_path, which holds a borrow
and now clones explicitly — the same copy the old &self join already made.

File::with_name / with_folder / with_size took &self and rebuilt the struct,
cloning every carried-over field (id, mime_type, folder_id, blob_hash, ...).
Consume self and mutate only the fields that change. Behaviour is identical;
the fallible builders now drop the input on Err, which is fine for these
rename/move/resize transforms (all current callers replace the file).

Impact is small in practice — with_folder/with_size have no callers and
with_name is test-only, while the one hot join caller (create_file_path)
must copy segments regardless — but the consuming form is the idiomatic one.

Verified: cargo fmt + clippy --all-features --all-targets -D warnings clean;
domain tests (path_service::, entities::file::) pass — 30 + 6.

https://claude.ai/code/session_01UtfkS3nZF1vrF5jNAps6wV

src/domain/entities/file.rs

@@ -388,45 +388,36 @@ impl File {
     // Methods to create new versions of the file (immutable)
 
     /// Creates a new version of the file with updated name
-    pub fn with_name(&self, new_name: String) -> FileResult<Self> {
+    pub fn with_name(mut self, new_name: String) -> FileResult<Self> {
         let new_name = normalize_storage_name(&new_name);
         if let Err(reason) = validate_storage_name(&new_name) {
             return Err(FileError::InvalidFileName(format!("{new_name}: {reason}")));
         }
 
-        // Update path based on name
-        let parent_path = self.storage_path.parent();
-        let new_storage_path = match parent_path {
+        // Recompute the path from the unchanged parent + the new name.
+        let new_storage_path = match self.storage_path.parent() {
             Some(parent) => parent.join(&new_name),
             None => StoragePath::from_string(&new_name),
         };
 
-        // Update string representation
-        let new_path_string = new_storage_path.to_string();
-
         let now = std::time::SystemTime::now()
             .duration_since(std::time::UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
 
-        Ok(Self {
-            id: self.id.clone(),
-            name: new_name,
-            storage_path: new_storage_path,
-            path_string: new_path_string,
-            size: self.size,
-            mime_type: self.mime_type.clone(),
-            folder_id: self.folder_id.clone(),
-            created_at: self.created_at,
-            modified_at: now,
-            owner_id: self.owner_id,
-            blob_hash: self.blob_hash.clone(),
-        })
+        // Consume `self` and mutate in place — only the path, name and mtime
+        // change; id / mime_type / folder_id / blob_hash are carried over
+        // without the per-field clone the old `&self` builder paid.
+        self.path_string = new_storage_path.to_string();
+        self.storage_path = new_storage_path;
+        self.name = new_name;
+        self.modified_at = now;
+        Ok(self)
     }
 
     /// Creates a new version of the file with updated folder
     pub fn with_folder(
-        &self,
+        mut self,
         folder_id: Option<String>,
         folder_path: Option<StoragePath>,
     ) -> FileResult<Self> {
@@ -436,49 +427,30 @@ impl File {
             None => StoragePath::from_string(&self.name), // Root
         };
 
-        // Update string representation
-        let new_path_string = new_storage_path.to_string();
-
         let now = std::time::SystemTime::now()
             .duration_since(std::time::UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
 
-        Ok(Self {
-            id: self.id.clone(),
-            name: self.name.clone(),
-            storage_path: new_storage_path,
-            path_string: new_path_string,
-            size: self.size,
-            mime_type: self.mime_type.clone(),
-            folder_id,
-            created_at: self.created_at,
-            modified_at: now,
-            owner_id: self.owner_id,
-            blob_hash: self.blob_hash.clone(),
-        })
+        // Consume `self`: only the path, folder_id and mtime change.
+        self.path_string = new_storage_path.to_string();
+        self.storage_path = new_storage_path;
+        self.folder_id = folder_id;
+        self.modified_at = now;
+        Ok(self)
     }
 
     /// Creates a new version of the file with updated size
-    pub fn with_size(&self, new_size: u64) -> Self {
+    pub fn with_size(mut self, new_size: u64) -> Self {
         let now = std::time::SystemTime::now()
             .duration_since(std::time::UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
 
-        Self {
-            id: self.id.clone(),
-            name: self.name.clone(),
-            storage_path: self.storage_path.clone(),
-            path_string: self.path_string.clone(),
-            size: new_size,
-            mime_type: self.mime_type.clone(),
-            folder_id: self.folder_id.clone(),
-            created_at: self.created_at,
-            modified_at: now,
-            owner_id: self.owner_id,
-            blob_hash: self.blob_hash.clone(),
-        }
+        // Consume `self`: only size and mtime change — no per-field clone.
+        self.size = new_size;
+        self.modified_at = now;
+        self
     }
 }
 

src/domain/services/path_service.rs

@@ -103,18 +103,16 @@ impl StoragePath {
         Self { segments }
     }
 
-    /// Appends a segment to the path.
+    /// Appends a segment to the path, consuming `self` so the existing
+    /// segment buffer is reused instead of deep-cloned.
     ///
     /// Traversal segments (`.`, `..`) and segments containing `/` are
     /// silently ignored to prevent path-traversal attacks.
-    pub fn join(&self, segment: &str) -> Self {
-        let mut new_segments = self.segments.clone();
+    pub fn join(mut self, segment: &str) -> Self {
         if Self::is_safe_segment(segment) {
-            new_segments.push(segment.to_string());
-        }
-        Self {
-            segments: new_segments,
+            self.segments.push(segment.to_string());
         }
+        self
     }
 
     /// Gets the file name (last segment)

src/infrastructure/services/path_service.rs

@@ -64,7 +64,9 @@ impl PathService {
 
     /// Creates a file path within a folder
     pub fn create_file_path(&self, folder_path: &StoragePath, file_name: &str) -> StoragePath {
-        folder_path.join(file_name)
+        // `join` consumes its receiver to reuse the buffer; we only hold a
+        // borrow here, so clone first — the same copy the old `&self` join did.
+        folder_path.clone().join(file_name)
     }
 
     /// Checks if a path is a direct child of another