Scripts and commands can run on remote compute providers

You can now run scripts and commands on remote compute providers. A script can declare FABRIK remote "microsandbox" or FABRIK remote "daytona", or a fabrik.toml [target.script] can set remote. On the CLI, fabrik run --remote --compute <provider> and fabrik exec --remote --compute <provider> run the action remotely. Cache misses are streamed live to the local console; cache hits replay the saved stdout, stderr, exit code, and outputs. The Daytona adapter uses the Daytona API directly, configured through FABRIK_DAYTONA_SANDBOX, FABRIK_DAYTONA_API_KEY (or DAYTONA_API_KEY), and an optional FABRIK_DAYTONA_API_URL.