* ci(devcontainer): retry Docker Hub syntax frontend and build
The devcontainers CLI injects `# syntax=docker/dockerfile:1`, which BuildKit
fetches from Docker Hub. Transient Hub timeouts caused main smoke failures
(run 26797815133). Pre-pull the frontend with backoff and retry the build
once, matching docker-build-push-retry policy.
Co-authored-by: Cursor <cursoragent@cursor.com>
* ci(devcontainer): address tri-review follow-ups on smoke retries
Make syntax-frontend pre-pull best-effort (continue-on-error) so build
retry still runs when Hub flakes only on pull. Clarify comment vs
docker-build-push-retry, and emit a notice when build retry succeeds.
Co-authored-by: Cursor <cursoragent@cursor.com>
---------
Co-authored-by: Cursor <cursoragent@cursor.com>