feat(docker): add dev.sh with auto-funding and ATM app setup

- Add dev.sh script for managing regtest development environment
- Implement cmd_fund to fund ATM app owner via Lightning.Pub API
- Add --fund flag to cmd_up for automatic funding on startup
- Update setup_atm_app to write VITE_APP_ID to machine .env
- Fix Electron IPC to pass appId and extensionApiUrl to renderer
- Restructure repo from nested lamassu-next/ to root

The dev.sh script now supports:
- ./dev.sh up --fund  # Start regtest and auto-fund ATM
- ./dev.sh fund       # Fund existing ATM app
- ./dev.sh status     # Show environment status
- ./dev.sh reset      # Clean restart

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/machine/src/lib/utils.ts

@@ -0,0 +1,7 @@
+import type { ClassValue } from 'clsx'
+import { clsx } from 'clsx'
+import { twMerge } from 'tailwind-merge'
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs))
+}