Initial CYD LD2420 radar dashboard with flashable firmware archive.

Presence uses ESPHome factory gates/timeout; OT1->GPIO22 RX->GPIO27; prebuilt bins under firmware/cyd_28r.

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

scripts/exclude_lvgl_asm.py

@@ -0,0 +1,13 @@
+"""Exclude LVGL Helium/Neon .S files that break ESP32 (xtensa) builds."""
+import shutil
+from pathlib import Path
+
+Import("env")  # type: ignore  # noqa: F821
+
+LIBDEPS = Path(env["PROJECT_LIBDEPS_DIR"]) / env["PIOENV"] / "lvgl"  # type: ignore  # noqa: F821
+
+for sub in ("draw/sw/blend/helium", "draw/sw/blend/neon"):
+    target = LIBDEPS / "src" / sub
+    if target.exists():
+        shutil.rmtree(target, ignore_errors=True)
+        print(f"Removed LVGL ASM path: {target}")