feat: enforce lint checks as gate for commits and CI (#54)

- Add PHP syntax check to lint-staged via scripts/lint-php.sh
- Add lint:php script to package.json
- Update lint script to include PHP checks
- Create scripts/safe-commit.sh for AI agent use
- Update deploy-test.yml: lint jobs as gate before deploy
- Add branch protection for main requiring status checks
- Update AGENTS.md with pre-commit hook rules for agents

Also addresses #53: CI requires lint checks before merge

Co-authored-by: Claw <claw@openclaw.local>

scripts/lint-php.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Pre-commit PHP syntax check for lint-staged
+# Called with staged .php files as arguments
+
+set -euo pipefail
+
+if ! command -v php &>/dev/null; then
+  echo "❌ PHP not found. Install php-cli to commit PHP files."
+  echo "   Ubuntu/Debian: sudo apt-get install php-cli"
+  exit 1
+fi
+
+errors=0
+for file in "$@"; do
+  if ! php -l "$file" >/dev/null 2>&1; then
+    echo "❌ Syntax error in $file"
+    php -l "$file"
+    errors=1
+  fi
+done
+
+if [ "$errors" -eq 1 ]; then
+  echo ""
+  echo "❌ PHP lint failed. Fix errors before committing."
+  exit 1
+fi
+
+echo "✅ PHP syntax OK"