Update dependencies and improve syncback handling

- Updated versions of several dependencies in `Cargo.lock`, including `async-compression` (0.4.40), `aws-lc-rs` (1.16.0), `bumpalo` (3.20.1), and `compression-codecs` (0.4.37), ensuring compatibility and access to the latest features and fixes.
- Refactored the `fire` method in `SyncbackSignal` to return a boolean indicating whether a syncback was successfully initiated, preventing concurrent syncbacks.
- Enhanced error handling in the API syncback process to return a conflict response if a syncback is already in progress.
- Improved the `serve.rs` file by replacing `forget` with `drop` for better memory management and added checks to ensure service chunk integrity during live syncback operations.
- Added new tests for edge cases and resilience in live syncback functionality, ensuring robustness against malformed data and rapid sequential requests.

These changes aim to enhance the reliability and performance of the syncback feature while keeping dependencies up to date.

src/cli/serve.rs

@@ -1,7 +1,6 @@
 use std::{
     collections::HashMap,
     io::Cursor,
-    mem::forget,
     net::{IpAddr, Ipv4Addr, SocketAddr},
     path::{Path, PathBuf},
     sync::Arc,
@@ -58,7 +57,7 @@ impl ServeCommand {
                 .port
                 .or_else(|| session.project_port())
                 .unwrap_or(DEFAULT_PORT);
-            forget(session);
+            drop(session);
             (ip, port)
         };
 
@@ -83,8 +82,12 @@ impl ServeCommand {
             match server.start(addr) {
                 ServerExitReason::SyncbackRequested(payload) => {
                     log::info!("Live syncback requested, running...");
-                    run_live_syncback(&project_path, payload)?;
-                    log::info!("Syncback complete, restarting serve...");
+                    match run_live_syncback(&project_path, payload) {
+                        Ok(()) => log::info!("Syncback complete, restarting serve..."),
+                        Err(err) => {
+                            log::error!("Live syncback failed: {err:#}. Restarting serve...")
+                        }
+                    }
                     continue;
                 }
             }
@@ -132,7 +135,7 @@ fn run_live_syncback(project_path: &Path, payload: SyncbackPayload) -> anyhow::R
 
     crate::git::refresh_git_index(base_path);
 
-    forget(session_old);
+    drop(session_old);
 
     Ok(())
 }
@@ -184,7 +187,15 @@ fn build_dom_from_chunks(payload: SyncbackPayload) -> anyhow::Result<WeakDom> {
         let child_count = chunk.child_count as usize;
         let ref_count = chunk.ref_target_count as usize;
         let total = child_count + ref_count;
-        let end = (cursor + total).min(cloned_children.len());
+        let end = cursor + total;
+        anyhow::ensure!(
+            end <= cloned_children.len(),
+            "Service '{}' claims {} children + {} carriers but only {} instances remain in blob",
+            chunk.class_name,
+            child_count,
+            ref_count,
+            cloned_children.len().saturating_sub(cursor)
+        );
         let service_range: Vec<Ref> = cloned_children[cursor..end].to_vec();
 
         for &child_ref in &service_range[..child_count.min(service_range.len())] {
@@ -210,6 +221,13 @@ fn build_dom_from_chunks(payload: SyncbackPayload) -> anyhow::Result<WeakDom> {
         cursor = end;
     }
 
+    anyhow::ensure!(
+        cursor == cloned_children.len(),
+        "Service chunks account for {} instances but rbxm blob contains {}",
+        cursor,
+        cloned_children.len()
+    );
+
     for &service_name in VISIBLE_SERVICES {
         if !created_services.contains(service_name) {
             dom.insert(root_ref, InstanceBuilder::new(service_name));