With a real codex login now available, record the one shape the fake-key
lab could never produce: a genuine model reply streaming above the pinned
composer, pushing lines into history (baseY grows) while keystrokes land
mid-stream. The recorder gains an opt-in CODEX_RECORD_REAL=1 scenario
using the user's own ~/.codex (fixture secret-scanned for key/JWT
material before writing; scanned clean). The replay test pins: baseY > 0,
mid-stream predictions painted, exact convergence to the typed text.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Mosh-style write-through prediction: the consumer sends every keystroke
unchanged; the addon paints predicted glyphs and reconciles against the
parsed buffer. Confirm = cell match + cursor advance (placeholder-safe,
repaint-safe); two-pass mismatch cascade with neutral blanks (measured:
codex clears its placeholder on first echo); TTL bound; baseY-based line
reads; scroll/resize/off-row clears. Zero edits to zerolag-input-addon.ts.
Tests: 30 addon-law specs + renderer geometry (fake performance clock for
TTL/grace), 6 replay suites running the real algorithm through a real
@xterm/headless parser fed by the recorded codex fixtures, and a
500-iteration seeded fuzz with per-op span/record + grid invariants.
227 total, the pre-existing 175 untouched.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>