components: ExpectedPages duplicates the site map and will drift

[joelpeace48-cell]

Problem

components/expected-pages.tsx hardcodes the route table as JSX rows, and its
own copy says the table "is the contract between product and engineering". The
same table exists in docs/SITE_MAP.md. Two hand-maintained copies of the same
truth will disagree — and the component itself is already stale, listing
/product and /contracts as "Planned" when both routes exist.

What to do

• Move the route data into a single typed module (lib/site-map.ts) with a
  Route type and an explicit status union.
• Render the component from that data.
• Generate docs/SITE_MAP.md from the same source in a script, and have CI fail
  when the committed markdown is stale.
• Correct the statuses to reflect reality.

Acceptance criteria

• Single typed source of route data
• Component and markdown both generated from it
• CI fails on stale generated docs
• Current statuses accurate

Notes

The staleness is the argument for the change: the table drifted within one
release of being written.