Sibling of #40 (composite output as a named multi-field record). Brings
the other two composite-boundary edge-kinds to the same named-projection
shape: input roles (Vec<Role { name, targets }>, rendered [in:<name>])
and a param-alias overlay (Vec<ParamAlias { name, node, slot }>) that
relabels an interior leaf param slot's surface name in param_space().
Load-bearing decision recorded in the spec: param aliasing is a pure
naming overlay, NOT curation — every interior slot stays in param_space()
and sweepable; the alias only relabels in place, never reorders/hides
(forced by the issue's "legibility not capability" framing + C23). The
injected point vector is unchanged; MACD surfaces macd.fast/slow/signal
instead of three indistinguishable macd.length.
Gates green: feature-acceptance (worked MACD before->after is the
evidence), placeholder scan clean, parse-every-block no-op (profile
declares no spec_validation), grounding-check PASS (7 load-bearing
assumptions each ratified by a named currently-green test; compiled_view
+ param_space slot-order goldens stand as the C23 regression anchors).
refs #41
Brummel
03f2dc4c51