feat(cloud): review Config files and redact SDK previews#1497

Summary

Review complete Config file text and permissions before deployment. Show the affected Services once per Config and expose both per-file and whole-Config discard.

Direct SDK previews and preparation results return a redacted copy. The executable plan keeps the original Config bytes. Literal review text is excluded from PostHog capture.

The user guide covers creation, mounts, references, review, permissions, and deployment. Progress and outcome payloads are outside this preview redaction change.

Evidence

• The native Node smoke regression passes for both preview routes. Sentinel text and byte arrays are absent from previews, while both captured container-creation requests retain the original bytes.
• The final integrated dashboard pnpm pr:check gate passes with 1,145 tests. Browser writes persist after reload, and discarding app.conf preserves app.conf.bak.
• On a disposable Machine, Cloud review shows full authored comparisons, custom file metadata, and exactly the two affected Services. Deploy replaces both mounters and preserves the unrelated control. An unchanged CLI redeploy preserves all three container identities.
• Both public JS preview routes omit the harmless sentinel on the real Machine. Branch Follow hints say File; accepting the exact file choice and reloading preserves the sibling.

Merge Danger

Door: Two-way.

Blast Radius: Review.

Malformed file comparisons fail visibly instead of exposing a raw JSON fallback. Exact Config file discard retains the existing descendant behavior for Service settings.

React Doctor retains the same 14 existing findings and 49/100 score as C5. This is not a clean Doctor result.