perf: Phase 2 rendering & cache optimizations

src/diff.rs

@@ -114,9 +114,12 @@ mod tests {
     use super::*;
 
     fn file(name: &str, size: u64) -> EntryInfo {
+        let name = name.to_string();
+        let path = PathBuf::from(&name);
         EntryInfo {
-            name: name.to_string(),
-            path: PathBuf::from(name),
+            lower_name: name.to_lowercase(),
+            name,
+            path,
             kind: EntryKind::File,
             size_bytes: Some(size),
             modified: None,
@@ -125,9 +128,12 @@ mod tests {
     }
 
     fn dir(name: &str) -> EntryInfo {
+        let name = name.to_string();
+        let path = PathBuf::from(&name);
         EntryInfo {
-            name: name.to_string(),
-            path: PathBuf::from(name),
+            lower_name: name.to_lowercase(),
+            name,
+            path,
             kind: EntryKind::Directory,
             size_bytes: None,
             modified: None,

src/fs.rs

@@ -9,6 +9,9 @@ use crate::action::CollisionPolicy;
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct EntryInfo {
     pub name: String,
+    /// Lower-case version of `name`, cached at construction to avoid repeated
+    /// `to_lowercase()` allocations during sorting and filtering.
+    pub lower_name: String,
     pub path: PathBuf,
     pub kind: EntryKind,
     pub size_bytes: Option<u64>,
@@ -164,6 +167,7 @@ pub fn scan_directory(path: &Path) -> Result<Vec<EntryInfo>, FileSystemError> {
             None
         };
         results.push(EntryInfo {
+            lower_name: name.to_lowercase(),
             name,
             path: entry_path,
             kind,
@@ -192,7 +196,7 @@ pub fn scan_directory(path: &Path) -> Result<Vec<EntryInfo>, FileSystemError> {
     results.sort_by(|left, right| {
         left.kind
             .cmp(&right.kind)
-            .then_with(|| left.name.to_lowercase().cmp(&right.name.to_lowercase()))
+            .then_with(|| left.lower_name.cmp(&right.lower_name))
     });
 
     Ok(results)

src/fs/local.rs

@@ -93,6 +93,7 @@ impl FsBackend for LocalBackend {
             None
         };
         Ok(EntryInfo {
+            lower_name: name.to_lowercase(),
             name,
             path: path.to_path_buf(),
             kind,

src/fs/scan_diff.rs

@@ -70,9 +70,12 @@ mod tests {
     use std::time::{Duration, SystemTime};
 
     fn entry(name: &str, kind: EntryKind, size: u64, mtime_offset_secs: u64) -> EntryInfo {
+        let name = name.to_string();
+        let path = PathBuf::from(&name);
         EntryInfo {
-            name: name.to_string(),
-            path: PathBuf::from(name),
+            lower_name: name.to_lowercase(),
+            name,
+            path,
             kind,
             size_bytes: Some(size),
             modified: Some(SystemTime::UNIX_EPOCH + Duration::from_secs(mtime_offset_secs)),

src/fs/sftp.rs

@@ -49,12 +49,14 @@ impl SftpBackend {
             EntryKind::Other
         };
 
+        let name = path
+            .file_name()
+            .and_then(|n| n.to_str())
+            .unwrap_or("")
+            .to_string();
         EntryInfo {
-            name: path
-                .file_name()
-                .and_then(|n| n.to_str())
-                .unwrap_or("")
-                .to_string(),
+            lower_name: name.to_lowercase(),
+            name,
             path: path.to_path_buf(),
             kind,
             size_bytes: Some(stat.size.unwrap_or(0)),
@@ -85,6 +87,7 @@ impl FsBackend for SftpBackend {
         // Add parent directory entry ("..")
         if let Some(parent) = remote_path.parent() {
             result.push(EntryInfo {
+                lower_name: "..".to_string(),
                 name: "..".to_string(),
                 path: parent.to_path_buf(),
                 kind: EntryKind::Directory,

src/jobs.rs

@@ -900,6 +900,7 @@ pub fn spawn_workers() -> (WorkerChannels, Receiver<JobResult>, Receiver<JobResu
                                         None
                                     };
                                     entries.push(EntryInfo {
+                                        lower_name: first.to_lowercase(),
                                         name: first.clone(),
                                         path: archive_path.join(first),
                                         kind,
@@ -913,7 +914,7 @@ pub fn spawn_workers() -> (WorkerChannels, Receiver<JobResult>, Receiver<JobResu
                             entries.sort_by(|l, r| {
                                 l.kind
                                     .cmp(&r.kind)
-                                    .then_with(|| l.name.to_lowercase().cmp(&r.name.to_lowercase()))
+                                    .then_with(|| l.lower_name.cmp(&r.lower_name))
                             });
                             let _ = result_tx.send(JobResult::ArchiveListed {
                                 workspace_id: req.workspace_id,
@@ -1005,6 +1006,7 @@ pub fn spawn_workers() -> (WorkerChannels, Receiver<JobResult>, Receiver<JobResu
                                     None
                                 };
                                 entries.push(EntryInfo {
+                                    lower_name: first.to_lowercase(),
                                     name: first.clone(),
                                     path: archive_path.join(first),
                                     kind,
@@ -1019,7 +1021,7 @@ pub fn spawn_workers() -> (WorkerChannels, Receiver<JobResult>, Receiver<JobResu
                     entries.sort_by(|l, r| {
                         l.kind
                             .cmp(&r.kind)
-                            .then_with(|| l.name.to_lowercase().cmp(&r.name.to_lowercase()))
+                            .then_with(|| l.lower_name.cmp(&r.lower_name))
                     });
                     let _ = result_tx.send(JobResult::ArchiveListed {
                         workspace_id: req.workspace_id,