Initial commit: VMware vSphere API simulator scaffold.

Add the FastAPI app, PostgreSQL migrations, Docker/Helm packaging, API
contracts, docs, client examples, and the unit/integration/compatibility
test suite for local client and tooling labs without a real vCenter.

tests/unit/test_migrations.py

@@ -0,0 +1,56 @@
+"""Migration discovery and checksum tests."""
+
+from pathlib import Path
+
+from app.db.migrations import load_migrations
+
+
+def test_load_migrations_is_ordered_and_checksummed(tmp_path: Path) -> None:
+    (tmp_path / "002_second.sql").write_text("SELECT 2;")
+    (tmp_path / "001_first.sql").write_text("SELECT 1;")
+
+    migrations = load_migrations(tmp_path)
+
+    assert [migration.version for migration in migrations] == [1, 2]
+    assert migrations[0].name == "001_first"
+    assert len(migrations[0].checksum) == 64
+
+
+def test_repository_migration_defines_required_planes() -> None:
+    migrations = load_migrations()
+    migration = migrations[0]
+
+    for table in (
+        "contract_snapshots",
+        "nodes",
+        "resources",
+        "principals",
+        "acl_entries",
+        "tasks",
+        "scenarios",
+        "audit_events",
+    ):
+        assert f"CREATE TABLE {table}" in migration.sql
+    assert "CREATE TABLE realms" in migrations[1].sql
+    assert "CREATE TABLE api_tokens" in migrations[1].sql
+    domain = migrations[3].sql
+    for table in (
+        "clusters",
+        "virtual_machines",
+        "containers",
+        "storages",
+        "storage_contents",
+        "snapshots",
+        "backups",
+        "pools",
+        "identity_groups",
+        "contract_paths",
+        "observed_contracts",
+        "scenario_rules",
+        "fault_injections",
+    ):
+        assert f"CREATE TABLE {table}" in domain
+    assert "CREATE TABLE group_acl_entries" in migrations[5].sql
+    assert "ADD COLUMN IF NOT EXISTS config jsonb" in migrations[6].sql
+    assert "CREATE TABLE tfa_entries" in migrations[7].sql
+    assert "CREATE TABLE openid_pending" in migrations[7].sql