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>

stubs/machine.py

@@ -0,0 +1,18 @@
+"""CPython stub for MicroPython `machine` (led-simulator)."""
+
+
+class Pin:
+    OUT = 1
+    IN = 0
+
+    def __init__(self, pin_id, mode=None, *, pull=None, value=None):
+        self.id = pin_id
+        self.mode = mode
+
+
+class WDT:
+    def __init__(self, timeout=10000):
+        self._timeout = timeout
+
+    def feed(self):
+        pass