Add SMB AAPL Extensions Phase 1-6 + VFS xattr support

Phase 1: AAPL Create Context negotiation
Phase 2: AFP_AfpInfo Stream structure (Finder info + creation time)
Phase 2.5: SMB Named Stream Backend (NamedStreamPath)
Phase 2.6: Backend Named Stream Support in handlers
Phase 2.7: VFS Extended Attributes (get/set/remove/list_xattr)
Phase 4: Time Machine share config (time_machine field)
Phase 5: Server/Volume Capabilities
Phase 6: macOS Unicode mapping (private range ↔ ASCII)

Tests: 174 smb-server tests pass, 52 VFS tests pass

vendor/smb-server/src/builder.rs

@@ -45,6 +45,8 @@ pub struct Share {
     pub(crate) backend: Arc<dyn ShareBackend>,
     pub(crate) mode: ShareMode,
     pub(crate) users: HashMap<String, Access>,
+    pub(crate) time_machine: bool,
+    pub(crate) time_machine_max_size: Option<u64>,
 }
 
 impl Share {
@@ -55,6 +57,8 @@ impl Share {
             backend: Arc::new(backend),
             mode: ShareMode::AuthenticatedOnly,
             users: HashMap::new(),
+            time_machine: false,
+            time_machine_max_size: None,
         }
     }
 
@@ -76,6 +80,20 @@ impl Share {
         self.users.insert(name.into(), access);
         self
     }
+
+    /// Enable Time Machine support for this share.
+    /// macOS clients will be able to use this share for backups.
+    pub fn time_machine(mut self) -> Self {
+        self.time_machine = true;
+        self
+    }
+
+    /// Set maximum backup size in GB for Time Machine.
+    pub fn time_machine_max_size(mut self, max_size_gb: u64) -> Self {
+        self.time_machine = true;
+        self.time_machine_max_size = Some(max_size_gb * 1024 * 1024 * 1024);
+        self
+    }
 }
 
 // ---------------------------------------------------------------------------
@@ -228,7 +246,7 @@ impl SmbServerBuilder {
         let mut share_bindings: Vec<Arc<ShareBindings>> = Vec::with_capacity(self.shares.len());
         for s in self.shares {
             share_bindings.push(ShareBindings::new(
-                s.name, s.backend, s.mode, s.users, false,
+                s.name, s.backend, s.mode, s.users, false, s.time_machine, s.time_machine_max_size,
             ));
         }