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>

examples/chase.py

@@ -0,0 +1,25 @@
+"""Simple one-pixel chase (uses preset c[0] for the dot, preset n3 as step)."""
+
+import utime
+
+
+class Chase:
+    def __init__(self, presets):
+        self.presets = presets
+
+    def run(self, preset):
+        n = self.presets.num_leds
+        rgb = preset.c[0] if preset.c else (255, 64, 0)
+        raw_step = int(getattr(preset, "n3", 1))
+        step = raw_step if raw_step != 0 else 1
+        pos = 0
+        delay_ms = max(1, int(preset.d))
+        while True:
+            off = (0, 0, 0)
+            for i in range(n):
+                self.presets.n[i] = off
+            self.presets.n[pos % n] = self.presets.apply_brightness(rgb, preset.b)
+            self.presets.n.write()
+            yield
+            utime.sleep_ms(delay_ms)
+            pos += step