This commit introduces a comprehensive Starlark scripting system that
enables custom automation with access to all subdaemon RPCs (lnd, loop,
pool, faraday, taproot-assets). Scripts use native LND macaroons for
permission enforcement.
Key features:
- Starlark execution engine with sandboxed resource limits
- Standard builtins: print, log, sleep, now, json_encode/decode
- HTTP GET requests with URL allowlisting
- Persistent KV store with bucket-based permissions
- LND event subscriptions for long-running daemon scripts
- Script CRUD operations with macaroon baking
- Execution history and running script tracking
- Complete CLI commands (litcli scripts ...)
Database schema:
- scripts: Store script definitions with macaroon permissions
- script_executions: Audit trail for script runs
- script_kv_store: Persistent key-value storage for scripts
- running_scripts: Track currently running scripts
Security model:
- Each script has an LND macaroon baked with specific permissions
- RPC calls from scripts include this macaroon in the header
- LND/subdaemons validate permissions natively
- URL and bucket allowlists validated at runtime
