Addresses PR #1402 review: the guard only claimed dominant-single, leaving
the symmetric bug open — the LLM can flatten a dominant-double/triple split
onto its minority single (e.g. "96% Double glazing 2002 or later, 4% Single").
A dominant double/triple whose era is explicit ("pre-2002" / "2002 or later")
is just as fully determined as era-free single, so the guard now claims it via
_DOMINANT_MEMBER. Only a genuinely ambiguous era ("unknown age", unstated) still
defers to the LLM — the "96% double -> None" contract now holds solely for the
era-unknown case, not the era-stated one.
Backfill script reuses the same guard, so it now corrects any dominant split;
renamed reclassify_dominant_single_glazing.py -> reclassify_dominant_glazing.py
to match. Tests cover double/triple x pre-2002/2002-or-later and the still-
deferred unknown-age case; 14 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A landlord glazing split like "4% Double glazing 2002 or later, 96% Single
Glazing" is a near-uniform *single*-glazing dwelling, but the LLM classifier
latched onto the 4% minority and wrote a "Double glazing…" override — over-
crediting the dwelling.
glazing_mix_guard rescued genuine mixes (no type >= 90%) to MIXED but returned
None for near-uniform splits, trusting the LLM to have applied the dominant type.
It hadn't. Single glazing is era-free, so a dominant-single split is fully
determined: the guard now returns SINGLE for it (dominant double/triple still
carry era ambiguity, so they stay the LLM's job — the existing "96% double" case
still defers).
Adds a portfolio-scoped backfill (reuses the same guard, so it can't drift from
the live path) and applied it to portfolio 796 (Hyde): 115 glazing overrides
corrected from a spurious Double back to Single.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
