feat: add IaC layer with shared var/t1 and var/t3 data paths

Ansible provisions the k3d cluster and Flux controllers; Terraform
modules deploy the simulated fleet and ground warehouse. Compose and
k3d share var/t1 (live lake) and var/t3 (warehouse). The prototype
gains a live mode fed by the explorer read-only SQL API.

simulator/explorer/server.py

@@ -116,9 +116,19 @@ class Handler(BaseHTTPRequestHandler):
         self.send_response(code)
         self.send_header("Content-Type", ctype)
         self.send_header("Content-Length", str(len(body)))
+        # Dev CORS: lets the prototype's live mode poll the API from another
+        # origin. Everything behind this is read-only by construction.
+        self.send_header("Access-Control-Allow-Origin", "*")
         self.end_headers()
         self.wfile.write(body)
 
+    def do_OPTIONS(self) -> None:  # noqa: N802 — http.server API
+        self.send_response(204)
+        self.send_header("Access-Control-Allow-Origin", "*")
+        self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
+        self.send_header("Access-Control-Allow-Headers", "Content-Type")
+        self.end_headers()
+
     def _json(self, payload: dict, code: int = 200) -> None:
         self._send(code, json.dumps(payload, default=str).encode(), "application/json")