docs(audits): the strictness ledger stops asserting a union flattening the tree no longer does

Three clauses in the unknown-key strictness ledger asserted, in the present
tense, that a strict branch's prescription is flattened away behind a union.
It is not: `formatZodIssue` descends `invalid_union` and ranks the branches
through `selectUnionBranches`, the one policy both spec-side walks import from
`packages/spec/src/shared/union-branch-policy.ts`.

Each clause is corrected in place, with its own provenance:

- the `state-machine.zod.ts` row (written 2026-08-04) and the `view.zod.ts`
  row's overlay note (written 2026-08-04) were TRUE when written and expired
  on 2026-08-05, when #4971 / #5014 / #5341 landed. They now say so and name
  the module that lifted it.
- the `chart.zod.ts` row's clause (written 2026-08-08) was already false the
  day it was written, so the row's own "kept as WRITTEN AT THE TIME" rule
  cannot rescue it. Its `only` is struck, and the generalisation it grounded
  — "a general constraint on every remaining union site in this campaign" —
  is withdrawn, because that generalisation is what seeded a false-premise
  card and cost a full dispatch cycle.

Rows whose claims are framed as what their own batch recorded are untouched,
and the os-regen `.counts.md` companion is not edited. No published surface
moves; the ledger is a repo-internal audit document.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016N6xmWt5hYm94ffVEwGH8x

Author: claude