refactor(storage-server): add SectorId, FileName, PackedPath newtypes, eliminate raw primitives and DRY violations

crates/servers/storage-server/src/filesystem.rs

@@ -11,27 +11,57 @@ impl FileHandle {
     }
 }
 
+pub const MAX_FILE_NAME: usize = 32;
+
+#[derive(Debug, Clone, Copy)]
+pub struct FileName {
+    bytes: [u8; MAX_FILE_NAME],
+    len: u8,
+}
+
+impl FileName {
+    pub fn empty() -> Self {
+        Self { bytes: [0; MAX_FILE_NAME], len: 0 }
+    }
+
+    pub fn from_bytes(src: &[u8]) -> Self {
+        let mut name = Self::empty();
+        let len = src.len().min(MAX_FILE_NAME);
+        name.bytes[..len].copy_from_slice(&src[..len]);
+        name.len = len as u8;
+        name
+    }
+
+    pub fn as_bytes(&self) -> &[u8] {
+        &self.bytes[..self.len as usize]
+    }
+
+    pub fn len(&self) -> usize {
+        self.len as usize
+    }
+}
+
+impl PartialEq<[u8]> for FileName {
+    fn eq(&self, other: &[u8]) -> bool {
+        self.as_bytes() == other
+    }
+}
+
 #[derive(Debug, Clone, Copy)]
 pub struct DirEntry {
-    pub name: [u8; 32],
-    pub name_len: u8,
-    pub size: u32,
+    pub name: FileName,
+    pub size: usize,
     pub is_dir: bool,
 }
 
 impl DirEntry {
     pub fn empty() -> Self {
         Self {
-            name: [0; 32],
-            name_len: 0,
+            name: FileName::empty(),
             size: 0,
             is_dir: false,
         }
     }
-
-    pub fn name_bytes(&self) -> &[u8] {
-        &self.name[..self.name_len as usize]
-    }
 }
 
 pub trait FileSystem {