Initial commit: SQL audit platform v0.1.0

FastAPI backend with auth, user, instance, ticket, query, dashboard APIs.
React + TypeScript frontend with mock data UI (10 pages).
SQLite + async SQLAlchemy, JWT auth, role-based access control.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/.env.example

@@ -0,0 +1,12 @@
+# DataGuard Backend Configuration
+ENV=development
+DEBUG=true
+SECRET_KEY=change-me-to-a-secure-random-string
+ACCESS_TOKEN_EXPIRE_MINUTES=30
+
+# Platform Database (SQLite)
+DATABASE_URL=sqlite+aiosqlite:///./sqlite3.db
+
+# Default Admin
+ADMIN_USERNAME=admin
+ADMIN_PASSWORD=123456