Function render_job_json 

pub fn render_job_json(job: &Job) -> Value

One background job, for acme-proxy jobs list/show and GET /api/jobs.

payload is echoed verbatim — it is the subject’s identity (an order id, a profile name), never a secret, which the migration guarantees so an operator can read the table with sqlite3. Every optional member is omitted when absent, never nulled; lastError is text a far end wrote, so a web surface must escape it (the .html templates do).