chore(hooks): enforce executable bit on claude.sh and build.sh via pre-commit hook

hooks/pre-commit

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Ensure control scripts stay executable.
+set -euo pipefail
+
+SCRIPTS=(claude.sh build.sh)
+
+for f in "${SCRIPTS[@]}"; do
+    if [[ -f "$f" && ! -x "$f" ]]; then
+        echo "pre-commit: fixing missing executable bit on $f"
+        chmod +x "$f"
+        git add "$f"
+    fi
+done