fix(release): handle tar failures properly in strict mode

Disable errexit temporarily around tar pipe to allow proper fallback
to cp+rm when tar fails. In strict mode (set -euo pipefail), pipe
failures would exit the function before the fallback could execute.

Changes:
- Wrap tar command with set +e / set -e
- Capture tar exit status explicitly
- Check status and fallback to cp if needed

This fixes intermittent sandbox test failures in strict parallel mode
while maintaining the performance benefit of tar on systems where it works.

Author: Chemaclass

release.sh

@@ -376,12 +376,19 @@ function release::sandbox::create() {
 
   # Copy repo content excluding .git, .release-state, node_modules
   # Try tar pipe first (faster), fallback to cp + rm for portability
-  if tar --exclude='.git' \
+  # Disable errexit temporarily to allow tar fallback in strict mode
+  local tar_status=0
+  set +e
+  tar --exclude='.git' \
     --exclude='.release-state' \
     --exclude='node_modules' \
     --exclude='.tasks' \
     --exclude='tmp' \
-    -cf - . 2>/dev/null | tar -xf - -C "$SANDBOX_DIR" 2>/dev/null; then
+    -cf - . 2>/dev/null | tar -xf - -C "$SANDBOX_DIR" 2>/dev/null
+  tar_status=$?
+  set -e
+
+  if [ "$tar_status" -eq 0 ]; then
     release::log_verbose "Copied project files to sandbox (tar)"
   else
     # Fallback: traditional cp + rm for maximum portability