Final pre-tag verification found four places where the docs did not
match the shipped artifact.
`TODO.md` `# Status` said the tag was held on a durability defect that
has since landed. Rewritten to record that it landed, without naming a
remaining blocker whose issue number would falsify the file the moment
it closes. `# Next Step` opened with "Land <that issue>" and is
corrected the same way.
The README Package Layout tree omitted `internal/reqtls`,
`internal/ciscript` and `internal/versionscript`, all three of which
exist; `reqtls` is named repeatedly in the surrounding prose as the
TLS predicate.
The README Authenticated Endpoints table omitted three live routes,
verified against `internal/server/routes.go`: `GET` and `POST` on
`/source/{id}/targets/{targetID}/edit`, and `GET
/source/{id}/logs/{eventID}/body`.
The Rationale section sold "Guaranteed delivery" without saying which
guarantee. The engine deliberately implements at-least-once: a send
whose bookkeeping write fails is left recoverable and sent again by
the pending sweep or the next restart. Stated plainly, with the
consequence for receivers.
Documentation only; no behaviour change.
