### wai-quantum-service: every job's energy, signed with its result

- **What a result carries.** `energy` holds the CPU energy of the job's worker process, from
  its start to its exit, inside the body the receipt seals. It is given as `joules_micro`,
  with the acquisition class `OnChipCounter`, a declared uncertainty
  (`relative_ppm`, `window_us`) and the counter's filtering state, in
  [energy-measurement](extensions/energy-measurement.md) §2's names. It also states its
  coverage and what it excludes.
- **How it is read.** On macOS, the service reads the worker's kernel count
  (`proc_pid_rusage`, `ri_energy_nj`, plus energy system services billed to it) after the
  worker has exited and before it is reaped, waiting with `waitid(WNOWAIT)`. An exited
  process has left every core, so the count is complete. The declaration covers the
  rounding to whole microjoules, and meets the §2.3 floor at every size.
- **What it does not claim.** A `statevector_single` job runs on the GPU, which the counter
  does not read, so its figure is `partial`. A job the service cannot read is
  `{"unmetered": why}`, never zero joules.
- **Agents.** The MCP summary states the figure and its coverage.

