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/compatibility/test_api_surface_probe.py

@@ -0,0 +1,38 @@
+"""CI gate: every declared method on majors 6-9 is callable without critical failures.
+
+Critical = HTTP 501, server 5xx, unhandled exceptions, or emulator-limitation
+strings. Synthetic 4xx (missing object / incomplete payload) are allowed.
+Requires PostgreSQL via ``TEST_DATABASE_URL``.
+"""
+
+from __future__ import annotations
+
+import os
+
+import pytest
+
+from app.surface_probe import run_probe
+
+pytestmark = [
+    pytest.mark.integration,
+    pytest.mark.skipif(not os.getenv("TEST_DATABASE_URL"), reason="TEST_DATABASE_URL is required"),
+]
+
+
+@pytest.mark.asyncio
+async def test_all_majors_surface_has_zero_critical_failures() -> None:
+    results = await run_probe()
+    assert len(results) == 4
+    for item in results:
+        version = item["version"]
+        declared = item["declared"]
+        assert item["implemented"] == declared, version
+        assert item["verified"] == declared, version
+        assert item["dimensions_min"] == declared, version
+        assert item["failure_count"] == 0, f"{version} critical failures: {item.get('failures')}"
+        by_verb = item["by_verb"]
+        for verb, buckets in by_verb.items():
+            assert buckets.get("unimplemented_501", 0) == 0, (version, verb, buckets)
+            assert buckets.get("unsupported_message", 0) == 0, (version, verb, buckets)
+            assert buckets.get("server_5xx", 0) == 0, (version, verb, buckets)
+            assert buckets.get("exception", 0) == 0, (version, verb, buckets)