[bolubo]

The real-machine work produced seconds (detect ≤10s, write 11–13s, seal 4–4.6s for 5.5 GiB), and they
started leaking into product pages. That is the wrong shelf: a user configures periods through
no-us/with-us, and a platform's grace is the environment's number.

What this does

• docs/operator-notes.md: the chain, the sizing formula
  grace ≥ (probe + round) + T_write + T_seal, the measured example (5.5 GiB, one box), how to get
  your own T_write (not with a single dd: it swings 5× with page cache), and the two constraints
  that must not be violated.
• README: no seconds left; it points at the page instead (693 words).
• docs/conditions.md keeps the cadence table (the catalogue's own property) and points to it.
• docs/index.md: listed under "If you are operating it"; docs/plan-library.md: 6.7.

Validation

make docs   47 pages, 52 local links, 0 dead
make fast   ok
README      693 words

Documentation only. The numbers come from experiments/real/ (s0/s1 and the first S2 cells), which
stay out of git by design.