A read-side cycle: `aura chart <family>` overlays one tap (default equity) of all
members of a sweep / MC / walk-forward family in one self-contained uPlot page,
consistent across kinds via the existing union-ts spine. The view consumes a
"set of runs to compare" (a family is its first producer) — the first step toward
the programmable analysis meta-level (C21), without rebuilding the orchestration
axes. aura-registry gains name_kind / read_family / ensure_name_free (a write-guard
making name resolution a total function); aura-cli gains the comparison ChartData
builder + emit_chart branch + --tap. aura-engine untouched (C9/C14).
Brainstorm-ratified, grounding-check PASS (11/11 current-behaviour assumptions
ratified by green tests). Signed under /boss on the grounding PASS.
refs #107
Brummel
5f31eccc7c