plan: 23.4 — mono-pass unification + prep2/prep3 rollback
Eleven tasks plus final regression smoke. Tasks 1-6 build the
unified mono pass incrementally (MonoTarget shape, N-ary naming,
free-fn synth, target collection, call-site rewrite, fixpoint
dispatch). Task 7 verifies poly_id/poly_apply/poly_rec_capture
regress green. Task 8 pins mono-symbol hashes. Task 9 removes
codegen-time lower_polymorphic_call + module_polymorphic_fns +
mono_queue. Task 10 reverts prep2 (a06159d) + prep3 (c42a0f5).
Task 11 amends DESIGN.md §Resolution-and-monomorphisation to
cover all Type::Forall Defs.
Implementer open commitments deferred per spec: MonoTarget shape
(enum vs Option), collector mechanism (synth-residual extension
vs separate walker), polymorphic Def::Fn retention post-mono,
subst.rs dead-code handling. Plan calls each out with a default
and NEEDS_CONTEXT permission for alternatives.
Brummel
ea0285b85f