Add LED tool: device, CLI, web UI, build scripts, and tests

- device.py: device communication/handling
- cli.py: CLI interface updates
- web.py: web interface
- build.py, build.sh, install.sh: build and install scripts
- Pipfile: Python dependencies
- lib/mpremote: mpremote library
- test_*.py: import and LED tests
- Updated .gitignore and README

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

test_imports.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python3
+"""Test script to verify imports work"""
+import sys
+import os
+
+# Test 1: Check if file exists
+transport_serial_path = 'lib/mpremote/transport_serial.py'
+print(f"1. Checking if {transport_serial_path} exists...")
+if os.path.exists(transport_serial_path):
+    print(f"   ✓ File exists ({os.path.getsize(transport_serial_path)} bytes)")
+else:
+    print(f"   ✗ File does NOT exist!")
+    sys.exit(1)
+
+# Test 2: Add lib to path and import
+print("2. Testing imports...")
+sys.path.insert(0, 'lib')
+try:
+    from mpremote.transport_serial import SerialTransport
+    print("   ✓ transport_serial import works")
+except Exception as e:
+    print(f"   ✗ transport_serial import failed: {e}")
+    sys.exit(1)
+
+# Test 3: Import device module
+try:
+    import device
+    print("   ✓ device module import works")
+except Exception as e:
+    print(f"   ✗ device module import failed: {e}")
+    sys.exit(1)
+
+# Test 4: Import cli module
+try:
+    import cli
+    print("   ✓ cli module import works")
+except Exception as e:
+    print(f"   ✗ cli module import failed: {e}")
+    import traceback
+    traceback.print_exc()
+    sys.exit(1)
+
+print("\n✓ All imports successful!")