T1 [high-1]: refine_multi_candidate_residual rigid-var filter now
requires class + type-unification via constraint_type_matches, so
forall a b. prelude.Show a, userlib.Show b => ... shapes discriminate
by which typevar the residual is on. Discharge-time only; synth-time
twin doesn't have a residual type to unify against (fresh metavar
constructed after dispatch).
T2 [high-2]: qualifier_is_class_shape extracted as pub(crate) helper
adjacent to parse_method_qualifier; broadened to accept PascalCase
single-segment qualifiers like Show.show alongside module-qualified
ones. Same-module bare-class call sites now reachable; symmetric to
mq.1 canonical-form rule.
T3 [medium-1]: any_candidate_class_has_instance pub(crate) helper
gates the class-method-shadowed-by-fn warning closure on registry
instance presence (any candidate class, any type). Conservative
tightening of the spec rule per Boss Q2 decision.
T4 [medium-2]: four DESIGN.md Data Model schema fragments
(SuperclassRef, InstanceDef.class, Type::Con.name, Constraint.class)
annotated with canonical-form cross-references.
Two trip-wires fixed inline: parse_method_qualifier docstring
coherence, mq3 in-crate test fixture-repair (registry instance
injection — analogous to mq.3 typeclass_22b3 pattern).
5/5 tasks. 548 tests green (was 545 + 3 new mq_tidy_* unit tests).
bench/compile_check.py + cross_lang.py exit 0; check.py exit 0
both runs with noise-class metric migration on
latency.implicit_at_rc.* max-tail (6th-consecutive observation
since audit-cma). Baseline pristine.
Brummel
1b6cbcb68b