refactor: flatten monorepo structure to backend/ frontend/ devops/

Rename subdirectories for a cleaner single-repo layout:
- website-monitoring-backend/  → backend/
- website-monitoring-frontend/ → frontend/
- website-monitoring-devops/   → devops/

Update all references in package.json scripts, CI workflows,
docker-compose, pre-commit hooks, and documentation.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/scripts/setup-database.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# Setup database for website monitoring frontend
+echo "Setting up database..."
+
+# Start PostgreSQL service if not running
+if ! pg_isready -h localhost -p 5432 > /dev/null 2>&1; then
+    echo "Starting PostgreSQL service..."
+    devenv up &
+    sleep 5
+fi
+
+# Create database and user if they don't exist
+psql -h localhost -U postgres -c "CREATE DATABASE website_monitoring;" 2>/dev/null || echo "Database already exists"
+psql -h localhost -U postgres -c "CREATE USER website_monitoring WITH PASSWORD 'password';" 2>/dev/null || echo "User already exists"
+psql -h localhost -U postgres -c "GRANT ALL PRIVILEGES ON DATABASE website_monitoring TO website_monitoring;" 2>/dev/null
+
+# Run the schema setup
+echo "Running database schema setup..."
+psql -h localhost -U website_monitoring -d website_monitoring -f setup-database.sql
+
+# Add missing column if it doesn't exist
+echo "Adding missing scheduled_at column..."
+psql -h localhost -U website_monitoring -d website_monitoring -c "ALTER TABLE scans ADD COLUMN IF NOT EXISTS scheduled_at TIMESTAMPTZ;"
+
+echo "Database setup complete!"