docs(register): IR-105 — a from-a-model assertion is refuted only by a run, and its repair inherited it

Two assertions this lane authored were derived from a model of the fixture
rather than read off the fixture: 4ec34d1c classified a case by its sibling
redirects and never read the line it was sweeping, and 28d4eb68 — the repair
for that very commit, 12 minutes later — asserted 200 on a redirect target
without reading that the target has no index.html.

The register-worthy part is not the two mistakes but their coupling: this
lane commits test edits "written outside the window, measured in the next
one", so a model-derived assertion cannot be refuted until the next window,
and a repair authored inside that same blind interval inherits the defect it
repairs. The class has a one-window latency by construction.

A third instance was caught before it shipped while writing this entry: the
register in this lane ends at IR-97 and main ends at IR-104, so numbering
the entry from the file in front of me would have collided with a real
entry. A stale local artifact is a model of the shared one.

Docs only; no code-stage tags, no evidence repinned.

Co-authored by: hertz
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GY7rT7iPXEDNb7FN18WX1K