diff --git a/.jules/bolt.md b/.jules/bolt.md
index bb6d4d8..1a8e67d 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -1,3 +1,6 @@
+## 2026-01-18 - [Shell Builtins vs Caching]
+**Learning:** Attempted to cache `command -v` results in a variable to avoid repeated checks. However, benchmarking revealed that `command -v` (a shell builtin) is extremely fast, and the overhead of checking a variable in shell script is comparable or even slower than the builtin itself. The optimization added complexity without performance gain.
+**Action:** Do not cache shell builtins like `command -v` unless inside a very tight loop with significant other overheads. Focus on avoiding external process spawns (like `jq`, `chmod`, `grep`) instead.
 ## 2026-01-16 - [Shell Dependency Check Overhead]
 **Learning:** `lib/core/common.sh` functions like `safe_json_get_key` re-check dependencies (`command -v jq`) on every invocation. In tight loops, this adds significant overhead (~13% in micro-benchmark).
 **Action:** Cache dependency checks in global variables (e.g., `_JSON_PROCESSOR_CACHE`) when the script is sourced, rather than checking inside hot functions.
diff --git a/bin/workflow-enforcer b/bin/workflow-enforcer
index 2a39727..73131b8 100755
--- a/bin/workflow-enforcer
+++ b/bin/workflow-enforcer
@@ -20,7 +20,7 @@ fi
 
 # Determine Project Root (where .adbs data is)
 # Default to current directory or ADBS_PROJECT_ROOT if set
-if [ -n "$ADBS_PROJECT_ROOT" ]; then
+if [ -n "${ADBS_PROJECT_ROOT:-}" ]; then
     PROJECT_ROOT="$ADBS_PROJECT_ROOT"
 else
     # Fallback: assume current directory is project root
@@ -44,12 +44,25 @@ DASHBOARD="$INSTALL_ROOT/lib/internal/dashboard.sh"
 mkdir -p "$PROJECT_ROOT/lib/internal"
 
 # Ensure scripts are executable
-if ! chmod +x "$WORK_MANAGER" "$TASK_BACKEND" "$MIGRATOR" "$PLATFORM_DETECTOR" "$DASHBOARD" 2>/dev/null; then
-    # chmod failed - likely on Windows or permission issue
-    # Check if scripts are already executable or if we're on Windows
-    if [ ! -x "$WORK_MANAGER" ] && [ "$(uname -s)" != "MINGW"* ] && [ "$(uname -s)" != "MSYS"* ]; then
-        echo "Warning: Could not make scripts executable. You may need to run:"
-        echo "  chmod +x lib/**/*.sh bin/*"
+# Performance: Check first to avoid spawning chmod process on every run
+_scripts_to_check=("$WORK_MANAGER" "$TASK_BACKEND" "$MIGRATOR" "$PLATFORM_DETECTOR" "$DASHBOARD")
+_needs_chmod=false
+
+for script in "${_scripts_to_check[@]}"; do
+    if [ ! -x "$script" ]; then
+        _needs_chmod=true
+        break
+    fi
+done
+
+if [ "$_needs_chmod" = true ]; then
+    if ! chmod +x "${_scripts_to_check[@]}" 2>/dev/null; then
+        # chmod failed - likely on Windows or permission issue
+        # Check if scripts are already executable or if we're on Windows
+        if [ ! -x "$WORK_MANAGER" ] && [ "$(uname -s)" != "MINGW"* ] && [ "$(uname -s)" != "MSYS"* ]; then
+            echo "Warning: Could not make scripts executable. You may need to run:"
+            echo "  chmod +x lib/**/*.sh bin/*"
+        fi
     fi
 fi
 
diff --git a/lib/internal/dashboard.sh b/lib/internal/dashboard.sh
old mode 100644
new mode 100755
diff --git a/lib/internal/migrator.sh b/lib/internal/migrator.sh
old mode 100644
new mode 100755
diff --git a/lib/internal/task_backend.sh b/lib/internal/task_backend.sh
old mode 100644
new mode 100755
diff --git a/lib/internal/work_manager.sh b/lib/internal/work_manager.sh
old mode 100644
new mode 100755
index 130961d..198b150
--- a/lib/internal/work_manager.sh
+++ b/lib/internal/work_manager.sh
@@ -406,33 +406,35 @@ export_context() {
 }
 
 # Main command handler
-case "${1:-}" in
-    create|new)
-        shift
-        create_work "$@"
-        ;;
-    list)
-        shift
-        list_work "$@"
-        ;;
-    show)
-        shift
-        show_work "$@"
-        ;;
-    context)
-        shift
-        export_context "$@"
-        ;;
-    complete|done)
-        shift
-        complete_work "$@"
-        ;;
-    status)
-        show_status
-        ;;
-    *)
-        echo "Unknown work command: ${1:-}"
-        echo "Usage: work_manager.sh {create|list|show|complete|status}"
-        exit 1
-        ;;
-esac
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+    case "${1:-}" in
+        create|new)
+            shift
+            create_work "$@"
+            ;;
+        list)
+            shift
+            list_work "$@"
+            ;;
+        show)
+            shift
+            show_work "$@"
+            ;;
+        context)
+            shift
+            export_context "$@"
+            ;;
+        complete|done)
+            shift
+            complete_work "$@"
+            ;;
+        status)
+            show_status
+            ;;
+        *)
+            echo "Unknown work command: ${1:-}"
+            echo "Usage: work_manager.sh {create|list|show|complete|status}"
+            exit 1
+            ;;
+    esac
+fi