Closes the second namespace sharing a first character with programme codes: the
usage prefixes b/t/l/k, under which a room silently inherited another room's
connectivity rules from its spelling.
usage is a plain, MANDATORY attribute of the space definition -- not a lookup
table. An interim design proposed a top-level usage_classes: table binding
author-coined names to behaviour; withdrawn, because an indirect name->behaviour
mapping living apart from the thing it describes is exactly the shape of the
prefix rule §39 exists to remove, it would be the only such table in a schema
where every other space property is a plain attribute, and the need it served
was already met -- "building specific" is about what a room is CALLED, and
name: is already free text.
Rule that settles it: a usage value exists iff the engine treats it differently
somewhere. Config selects among behaviours; it cannot invent them.
- programme.USAGES (living/kitchen/bedroom/toilet/utility/none) plus the
behaviour groupings PRIVATE_USAGES / PRIVATE_STRIPS / TOILET_STRIPS /
SOCIABLE_USAGES. Missing or unknown usage is a load error naming the code,
from BOTH parse paths.
- Code-level, never leaf-level: usage_of(leaf.type) is looked up fresh, so a
retype changes the class automatically. 51 sites assign leaf.type, and
share/share_type plus the r5a resurrection are the precedent for why
leaf-level attributes rot.
- graph.has_circulation takes the usage map and trims on declared class;
fitness.access and the public-access check likewise. fitness._t0 is DELETED --
no first-character type test remains anywhere in the codebase.
- utility is distinct from bedroom (same access requirements today) because it
is a different use and gives derive_interchange_classes an axis to relax on.
- A toilet now keeps its edge to a terminal room -- the Brand adjacency, which
the old b-before-t loop ordering severed.
- All 107 corpus entries migrated by experiments/migrate_usage_key.py, comments
and layout preserved.
MEASURED -- the connectivity model was ~4x too permissive. `none` is not
neutral: nothing is trimmed, so the graph may route THROUGH the room, and 34 of
52 codes had no class (Dental Surgery, Records Room, Utilities Closet all served
as corridors). Edges trimmed, prefix-inferred vs declared, 3 seeds each:
harbor-house 18 (9%) -> 79 (39%) inaccessible fails 0 -> 4
health-centre 12 (8%) -> 59 (40%) inaccessible fails 2 -> 3
maple-court 53 (17%) -> 123 (39%) inaccessible fails 1 -> 5
Re-baseline (seed 1, 20k, harbor): 58 fails (15h/43s) -> 61 (16h/45s), now
reporting 1-inaccessible-usable-space x2 plus level 0 and level 1 not connected.
The count rose because the objective got honest -- those failures were always
true of the layout and the old model could not see them. Every harbor number
before this was measured against a graph crediting routes through store
cupboards.
Sharpens §38.2: the objective pays x60-85 to delete circulation, and until now
the deleted corridors were not missed because storage stood in for them. With
that substitution gone, homemaker-py-2v1 is the remaining half -- and now
measurable, because the fails it should prevent actually fire.
350 passed (+5 new), same 7 pre-existing fixture failures, lint unchanged.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MJ84Feep79Hhm3E4zZJmnB
03aadec1ba