Brummel
69d20949c0
Collapse the two correctness-neutral debt items the 0021 fan-in pre-pass left behind (architect drift review at cycle close). Alias-validity: the `BadInteriorIndex` check was raised in two places — the structural pre-pass `check_composite_fan_in` and `inline_composite`. Since `compile_with_params` runs the pre-pass over every composite before any lowering, `inline_composite`'s copy was dead for that error path. The check now lives in one helper `check_alias_indices`, called solely by the pre-pass; `inline_composite` drops its copy (and the now-unused `param_aliases` binding — the overlay is a pure naming layer, unused in lowering, which is driven by the injected scalar vector). Alias-count: the per-node `a.node == node` predicate was re-derived in three spots (signature base, the unaliased-param test, the CLI render base-length). All three now route through one exported anchor `aliases_on`, so an alias-semantics change touches one site. Behaviour-preserving: the full workspace suite is the guard (15+6 cli, 25 core, 69 engine, 6+1+1 ingest/misc, 29 std — 0 failed), `out_of_range_param_alias_rejected` still green (now raised by the pre-pass), clippy -D warnings clean. No ledger change (the C9 refinement landed in 0021). closes #45