Iteration 1 (persist half) of the visual face — spec 0056 / plan 0055:
tap data from a graph and save it to disk so it can later be charted
(the serve/chart half is iteration 2).
- ColumnarTrace (aura-engine): a drained tap <-> columnar SoA form
({tap, kinds, ts, columns}); values coerced to f64 for plotting with
the base type preserved in `kinds` (C7); to_rows rebuilds uniformly-f64
rows for the serve-side join. Pure (C1), beside join_on_ts/summarize.
- TraceStore (aura-registry): a per-run directory under
runs/traces/<name>/ — one <tap>.json per tap + an index.json (manifest
+ tap order), beside the families.jsonl sibling store. Missing run =
NotFound (no panic); corrupt file = Parse{file}.
- CLI: a shared persist_traces helper threaded into run_sample /
run_macd / run_sample_real via an orthogonal `trace: Option<&str>`;
new arms `aura run [--macd] --trace <name>` and `--trace <name>` on
`run --real`. The default (no --trace) run is byte-for-byte unchanged.
Verified by the orchestrator: `cargo test --workspace` green (incl. the
4 columnar_trace, 3 trace_store, 4 cli_run e2e, and the 4-tuple
parse_real_args tests); `cargo clippy --workspace --all-targets -D
warnings` exit 0. Implementer deviations folded in, all
compiler-prescribed: #[derive(Debug)] on RunTraces (the RED tests
panic-format a Result over it), #[allow(clippy::type_complexity)] on
the parse_real_args 4-tuple (mirrors the crate's sample_harness idiom).
Default-run byte-identity stays pinned by run_prints_json_and_exits_zero.
refs #101
Brummel
8bb5256041