Replace OnceLock with Mutex<Option<Docker>> in the Rust backend so
failed Docker connections are retried instead of cached permanently.
Add frontend polling (every 5s) when Docker is initially unavailable,
stopping once detected.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Tauri v2 desktop app (React/TypeScript + Rust) for managing
containerized Claude Code environments. Includes Gitea Actions
workflow for building and pushing the sandbox container image,
and a BUILDING.md guide for manual app builds on Linux and Windows.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
