`aura chart <name>` now branches on the name's on-disk kind: a single run charts
its taps as before; a FAMILY overlays one tap (default equity) across all its
members in one self-contained uPlot page, consistent across sweep / MC /
walk-forward. Members share ONE y-scale (they measure one quantity — that is what
makes the overlay comparable, unlike the single-run overlay of different taps),
and align on the union-ts spine via the existing join_on_ts: sweep/MC members
share the window (true overlay), walk-forward members are disjoint OOS windows
(null-complementary -> the stitched curve). One mechanism, three correct readings.
- build_comparison_chart_data (one labelled Series per member, shared y_scale_id);
filter_to_tap (single-run --tap restricts to one tap; no --tap = all taps,
unchanged); parse_chart_args (`<name> [--tap <t>] [--panels]`, any order);
emit_chart name-kind branch; USAGE updated.
- Write-guard: ensure_name_free is now called once per tracing command (run /
run --macd / run --real -> Run; sweep / mc / walkforward -> Family) so a name
cannot be reused across kinds — name resolution stays a total function.
Refuse-don't-guess throughout (exit 2, never panic). Engine untouched (C9/C14).
Tasks 2-3 of plan 0061; Task 1 (registry) landed in 9b2adcb.
Verified: cargo test --workspace green (no failures; new unit + integration tests
incl. family-overlay, single-run --tap filter, cross-kind collision RED-then-green),
cargo clippy --workspace --all-targets -D warnings clean, cargo build --workspace
clean. Benign clippy-forced deltas vs the literal plan (no behaviour change): a
local MemberRows type alias (type_complexity), let-chains in the six guards
(collapsible_if), and dropping the now-dead TraceStoreError import.
closes#107
Brummel
4c64feb9ed