security: Add explicit permissions and security scanning workflow

- Add explicit permissions to all workflows (format, release, ci, test, label-issues, mark-answered)
- Fix format.yml to have write permissions for PR creation
- Add security.yml workflow for automated vulnerability scanning
- Improve security posture with minimal permissions principle

.github/scripts/format-code.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# Code formatting script
+# Formats code with black and sorts imports with isort
+
+set -e
+
+echo "🎨 Formatting code..."
+
+# Activate virtual environment if it exists
+if [ -d "venv" ]; then
+    source venv/bin/activate
+fi
+
+# Check if directories exist
+if [ ! -d "semantica" ]; then
+    echo "❌ semantica/ directory not found"
+    exit 1
+fi
+
+# Format with black
+echo "📝 Formatting with black..."
+black semantica/
+echo "✅ Black formatting complete"
+
+# Sort imports with isort
+echo "📦 Sorting imports with isort..."
+isort semantica/
+echo "✅ Import sorting complete"
+
+echo ""
+echo "✅ Code formatting complete!"
+