feat(infra): add Terraform config for nested PVE test VM

Provisions a throwaway nested Proxmox VE instance on an existing host
using bpg/proxmox provider. Includes unattended install via answer file,
API wait script, and automatic API token creation. Designed for CI-driven
integration test environments.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/infrastructure/scripts/wait-for-api.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+HOST="$1"
+PORT="${2:-8006}"
+MAX_WAIT="${3:-600}"
+INTERVAL=10
+
+echo "Waiting for PVE API at https://${HOST}:${PORT}..."
+elapsed=0
+while [ $elapsed -lt $MAX_WAIT ]; do
+    if curl -sk --connect-timeout 5 "https://${HOST}:${PORT}/api2/json/version" 2>/dev/null | grep -q '"version"'; then
+        echo "PVE API is responsive after ${elapsed}s"
+        exit 0
+    fi
+    echo "  Not ready yet (${elapsed}s elapsed)..."
+    sleep $INTERVAL
+    elapsed=$((elapsed + INTERVAL))
+done
+
+echo "ERROR: PVE API not responsive after ${MAX_WAIT}s"
+exit 1