feat(milestone): merge phase/01 operator-foundation → milestone/v0.4-operator-tier

Phase 1 complete — Operator Foundation:
- Postgres 16 in Docker-in-LXC (asyncpg pool, 5-table schema, PgStore, migrations)
- Operator auth (argon2id, signed stateless cookies, slowapi 5/min rate limit)
- VC issuer key migration SQLite→Postgres (archive-before-active, R-VC-MIG-01)
- Operator bootstrap CLI (create-operator.py, idempotent)
- Backup cron script + G-008 restore drill
- Graceful degradation (server starts without Postgres)
- 272 tests pass, 33 skip (Postgres-requiring), 0 fail

---ci---
project: praxis
phase: 1
milestone: v0.4
status: complete
requirements:
  covered: [REQ-MT-01, REQ-AUTH-01, REQ-NFR-AUTH-01, REQ-NFR-MT-01, REQ-MT-02]
  partial: []
---/ci---

server/auth/models.py

@@ -0,0 +1,18 @@
+"""Auth data models (TASK-03-04)."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass
+class Operator:
+    """The authenticated operator injected into protected routes (D-057)."""
+
+    id: str
+    username: str
+    display_name: str | None
+    role: str
+
+
+__all__ = ["Operator"]