docs: record what the extra verification found, and correct two claims

The previous handoff commit said doc-tests and example execution never ran.
Both have now run: 73 doc-tests pass, `probe_readers` runs clean, and
`simon snapshot --format text` was read rather than merely exited.

Reading it paid, as it did for the five defects in the original batch. The
camera fix is now confirmed against hardware instead of against a narrowed WMI
query: board.camera.{0,1} are a Lenovo 510 IR and a Lenovo 510 RGB, one
dual-sensor Windows Hello webcam correctly reported as two rows, with the
Brother scanner gone.

Also corrects an over-reading of the probe table that this file itself
encouraged. The nine "silent" readers printed `ok 0`, which says the monitor
constructed and enumerated nothing -- not that the machine lacks the hardware.
This desktop plainly has an IOMMU and thermal zones. `f2b998c` splits that into
`none`, and the note now says `none` is still ambiguous between "absent here"
and "unimplemented here" until each reader carries a reason.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>