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.

app/db/migrations/009_vsphere.sql

@@ -0,0 +1,30 @@
+-- Native vSphere inventory + sessions (independent of Proxmox resources).
+
+CREATE TABLE vsphere_sessions (
+    id text PRIMARY KEY,
+    username text NOT NULL,
+    created_at timestamptz NOT NULL DEFAULT now(),
+    expires_at timestamptz NOT NULL
+);
+
+CREATE INDEX vsphere_sessions_expires_idx ON vsphere_sessions (expires_at);
+
+CREATE TABLE vsphere_objects (
+    moid text PRIMARY KEY,
+    type text NOT NULL,
+    name text NOT NULL,
+    parent_moid text REFERENCES vsphere_objects (moid) ON DELETE SET NULL,
+    props jsonb NOT NULL DEFAULT '{}'::jsonb,
+    created_at timestamptz NOT NULL DEFAULT now(),
+    updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX vsphere_objects_type_idx ON vsphere_objects (type);
+CREATE INDEX vsphere_objects_parent_idx ON vsphere_objects (parent_moid);
+CREATE INDEX vsphere_objects_name_idx ON vsphere_objects (name);
+
+CREATE TABLE vsphere_credentials (
+    username text PRIMARY KEY,
+    password_hash text NOT NULL,
+    roles text[] NOT NULL DEFAULT '{Administrator}'
+);