macOS Time Machine AFP monitoring: backup_time update on file modification

- Added afp_monitor.rs module to track AFP_AfpInfo backup_time
- Open struct now has 'modified' flag to track file modifications
- write.rs sets modified=true on successful write
- close.rs calls AfpMonitor::update_backup_time() on modified files
- create.rs calls AfpMonitor::init_afp_info() on new file creation
- AFP_AfpInfo stored as xattr com.apple.aapl.AfpInfo
- backup_time updated to current epoch time on modification

Also includes:
- LZ4 compression using lz4_flex crate
- Case sensitivity conditional on backend capabilities
- LDAP cfg feature gate fix
- RAID rebuild reconstruction implementation
- DOS attributes xattr persistence
- Snapshot disk persistence

Tests: 201 smb-server, 452 markbase-core (653 total)

markbase-core/src/cli/tools/smb_server.rs

@@ -164,9 +164,11 @@ pub async fn handle_smb_server_command(cmd: SmbServerCommand) -> anyhow::Result<
                     user
                 };
 
-                let ldap_provider: Option<Arc<crate::provider::ldap::LdapProvider>> = if ldap {
-                    #[cfg(feature = "ldap")]
-                    {
+                #[allow(unused_mut)]
+                let mut ldap_enabled = false;
+                #[cfg(feature = "ldap")]
+                {
+                    if ldap {
                         let config = crate::provider::ldap::LdapConfig {
                             ldap_url: ldap_url.unwrap_or_else(|| "ldap://localhost:389".to_string()),
                             base_dn: ldap_base_dn.unwrap_or_else(|| "dc=example,dc=com".to_string()),
@@ -182,16 +184,13 @@ pub async fn handle_smb_server_command(cmd: SmbServerCommand) -> anyhow::Result<
                             user_groups_attr: ldap_user_groups_attr.unwrap_or_else(|| "memberOf".to_string()),
                         };
                         log::info!("LDAP authentication enabled: url={}, search_base={}", config.ldap_url, config.user_search_base);
-                        Some(Arc::new(crate::provider::ldap::LdapProvider::new(config)))
+                        ldap_enabled = true;
                     }
-                    #[cfg(not(feature = "ldap"))]
-                    {
-                        log::warn!("LDAP authentication requested but ldap feature not enabled");
-                        None
-                    }
-                } else {
-                    None
-                };
+                }
+                #[cfg(not(feature = "ldap"))]
+                if ldap {
+                    log::warn!("LDAP authentication requested but ldap feature not enabled");
+                }
 
                 let mut builder = SmbServer::builder().listen(addr);
 
@@ -210,7 +209,7 @@ pub async fn handle_smb_server_command(cmd: SmbServerCommand) -> anyhow::Result<
                 log::info!("SMB server listening on {}", addr);
                 log::info!("Share '{}' at root: {}", share_name, root);
                 log::info!("Users: {}", user_list.join(", "));
-                if ldap_provider.is_some() {
+                if ldap_enabled {
                     log::info!("LDAP authentication: enabled");
                 }