consort 0.11.0 — Codex account failover, Termscape account discovery

Added

• Codex account failover: CONSORT_CODEX_HOMES. A :-separated list of
  CODEX_HOME directories, one per Codex account, tried in order. A call
  moves on only when codex reports a usage or rate limit in its own error
  events or stderr (the exec transport now runs --json); the transcript is
  never read for it. Any other failure stops the walk. @default and
  @termscape expand to the inherited home and to every Codex account
  Termscape (nodeterm) has signed in (system account, then
  ~/.nodeterm/cx/<sha256(userData\0id)[:16]>). One stderr line per attempt
  names the home that ran. A home list forces the exec transport (the
  plugin broker is pinned to one account) and refuses an explicit
  CONSORT_CODEX_BACKEND=plugin. Delegation fails over only when the
  limited attempt did no work at all (no item in codex's event stream), so
  a half-applied edit or a leftover background process never reaches a
  second account. Keyring-backed logins (no auth.json) are recognised via
  codex login status. Only error events and a work-item count are kept
  from the stream; the transcript never touches disk. The Codex probe walks
  the same list. Tests: scripts/codex-backend.test.sh (stub codex).
• Hardened by the gate on this change (Codex, Gemini via Pi, blind security
  agent): the first cut fingerprinted the work tree with git add -A in a
  throwaway index, which ran the repo's core.fsmonitor, wrote untracked
  files into .git/objects and missed edits to ignored files; replaced by
  the no-work rule above. A malformed Termscape settings.json no longer
  echoes its offending line (it can hold an API key); a refused call clears
  a stale result file; the walk and the probe survive a caller's
  set -euo pipefail without || true.

Fixed

• codex exec calls without a payload and the Codex probe now read stdin
  from /dev/null; before, a call with no payload could sit on "Reading
  additional input from stdin..." when it inherited an open pipe that never
  closed (a harness or a background job).