feat(simulator): add GUI runner, stubs, and workspace assets

Add host simulator scaffolding, examples, and docs so led-driver main can run end-to-end with MicroPython module stubs.

Co-authored-by: Cursor <cursoragent@cursor.com>

settings.default.json

@@ -0,0 +1,13 @@
+{
+  "led_pin": 10,
+  "num_leds": 32,
+  "color_order": "rgb",
+  "name": "sim",
+  "debug": false,
+  "default": "on",
+  "brightness": 255,
+  "transport_type": "wifi",
+  "wifi_channel": 1,
+  "ssid": "",
+  "password": ""
+}