Initial commit: PESCO NCR system

Complete Non-Conformance Report system replacing the PowerApps/SharePoint
prototype: FastAPI + SQLAlchemy 2 (async) + Alembic + MySQL 8 backend,
React 18 + Vite + TypeScript + MUI frontend, Entra ID auth (MSAL / JWKS,
group-gated), Microsoft Graph delegated Mail.Send notifications (OBO),
six-stage workflow state machine with server-side enforcement, atomic
NCR-YYYY-NNNN numbering, attachments with camera capture, immutable
field-level audit trail, admin reopen, reports + CSV export, WeasyPrint
PDF traveler, Power BI reporting views + read-only DB user, documented
VISUAL ERP job-lookup stub, pytest suite (26 tests), docker-compose
deployment.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/app/models/base.py

@@ -0,0 +1,12 @@
+from datetime import datetime, timezone
+
+from sqlalchemy.orm import DeclarativeBase
+
+
+def utcnow() -> datetime:
+    """Naive UTC timestamp — all datetimes are stored as UTC in MySQL DATETIME."""
+    return datetime.now(timezone.utc).replace(tzinfo=None)
+
+
+class Base(DeclarativeBase):
+    pass