Expose preview/session evidence refs for accountable transfer review

[chubes4]

Goal

Expose stable, reviewer-safe preview/session evidence refs that Studio Web can attach to Conductor transfer-review records.

Why

Studio Web owns product preview links, and WP Codebox owns the disposable browser Playground session behind those previews. Conductor should not mint or interpret preview URLs, but the product review needs refs proving which preview/session backed a transfer review and approval.

Requirements

• Provide stable session/run refs for a browser Playground preview.
• Expose preview readiness/progress refs suitable for product evidence.
• Expose package/runtime component refs without local paths or secret values.
• Keep refs durable enough for Studio Web persisted review history.
• Avoid changing runtime mutation behavior.

Acceptance criteria

• Studio Web can persist a preview/session evidence ref without storing local file paths, localhost-only URLs, or secrets.
• Refs can be included in Conductor transfer-review/v1 target evidence.
• Existing browser session flows continue to work.

References

• Conductor Studio Web path: https://github.a8c.com/chubes4/conductor/issues/21
• Studio Web review panel: https://github.a8c.com/chubes4/studio-web/issues/407

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafting tracker language from Studio Web/Conductor review evidence requirements.