# `aura run` end-to-end sample-harness CLI — Implementation Plan

> **Parent spec:** `docs/specs/0010-aura-run-cli.md`
>
> **For agentic workers:** REQUIRED SUB-SKILL: use the `implement` skill to run
> this plan. Steps use `- [ ]` checkboxes for tracking.

**Goal:** Ship a reusable `aura-std::Recorder` sink node and wire an `aura run`
subcommand that bootstraps a sample SMA-cross→Exposure→SimBroker harness with two
recording sinks, runs it deterministically, and prints the cycle-0009
metrics+manifest report as canonical JSON to stdout.

**Architecture:** Two deliverables in dependency order. (1) `aura-std::Recorder`
— a pure consumer (`output: vec![]`, C8) over `kinds.len()` input columns,
holding an `mpsc::Sender<(Timestamp, Vec<Scalar>)>`, sending `(ctx.now(), row)`
each fired cycle once every column is warm and returning `None`; it mirrors the
existing `#[cfg(test)]` four-kind fixture in `harness.rs`. (2) `aura-cli` gains
`synthetic_prices` / `sample_harness` / `run_sample` / `main`: the sample harness
is authored in plain Rust over the raw `Harness::bootstrap(nodes, sources, edges)`
API (no builder DSL), and `main` hand-parses one subcommand. No `aura-engine` /
`Harness` / node-contract change; pure-additive; the workspace stays
zero-(external-)dependency.

**Tech Stack:** `aura-core` (`Node`/`Ctx`/`Scalar`/`Firing`/`Timestamp`),
`aura-engine` (`Harness::bootstrap`/`run`, the `report` surface — `summarize` /
`f64_field` / `RunManifest` / `RunReport`), `aura-std` (`Sma`/`Sub`/`Exposure`/
`SimBroker` + the new `Recorder`), `std::sync::mpsc`.

---

## Files this plan creates or modifies

- Create: `crates/aura-std/src/recorder.rs` — the shipped `Recorder` sink node
  (pure consumer, four-kind, holds `mpsc::Sender`).
- Modify: `crates/aura-std/src/lib.rs:18-29` — add `mod recorder;` and
  `pub use recorder::Recorder;` (alphabetical position: between `lincomb` and
  `sim_broker`).
- Modify: `crates/aura-cli/Cargo.toml:12-13` — add `aura-std` and `aura-core`
  path deps alongside `aura-engine`.
- Modify: `crates/aura-cli/src/main.rs:1-8` — replace the stub with
  `synthetic_prices` / `sample_harness` / `run_sample` / `main` + a unit-test
  module.
- Create: `crates/aura-cli/tests/cli_run.rs` — integration test driving the built
  binary via `env!("CARGO_BIN_EXE_aura")`.
- Test: `crates/aura-std/src/recorder.rs` (inline `#[cfg(test)] mod tests`) —
  Recorder captures a known f64 stream + returns `None` until all columns warm.
- Test: `crates/aura-cli/src/main.rs` (inline `#[cfg(test)] mod tests`) —
  `run_sample` determinism + pinned metric values.
- Test: `crates/aura-cli/tests/cli_run.rs` — `run` → exit 0 + JSON stdout; bad
  args → exit 2 + usage stderr.

---

## The chosen synthetic stream and its hand-computed metrics (load-bearing)

`synthetic_prices` is the 7-tick f64 stream below (rises through t=4, then
reverses), chosen so the demo trace is non-trivial — exactly one exposure sign
flip and a real drawdown (C22 populated trace):

```
t:      1       2       3       4       5       6       7
price:  1.0000  1.0010  1.0030  1.0060  1.0040  1.0010  0.9990
```

Tracing the cycle-0007 chain (topo order 0=Sma2, 1=Sma4, 2=Sub, 3=Exposure,
4=SimBroker, 5=equity sink, 6=exposure sink; the whole signal chain propagates
within one cycle, the broker lags exposure one cycle by its own state, C2):

- `Sma2_t = (p_t+p_{t-1})/2` (from t=2); `Sma4_t = mean(last 4)` (from t=4).
- `spread_t = Sma2_t - Sma4_t`; `exposure_t = clamp(spread/0.5, -1, +1) = 2·spread`
  (in-band, no clamp): `expo = [+0.004, +0.003, -0.002, -0.005]` for t=4..7.
- Exposure node produces (and the exposure sink records) only t=4..7 → exposure
  rows `[+0.004, +0.003, -0.002, -0.005]`; sign sequence `+,+,-,-` → **1 sign
  flip**.
- SimBroker (`pip_size=0.0001`) fires every cycle, integrating
  `prev_exposure·(price-prev_price)/pip_size`; equity recorded t=1..7 is
  `[0, 0, 0, 0, -0.08, -0.17, -0.13]`:
  - t5: `0.004·(1.0040-1.0060)/0.0001 = 0.004·(-20) = -0.08` → cum `-0.08`
  - t6: `0.003·(1.0010-1.0040)/0.0001 = 0.003·(-30) = -0.09` → cum `-0.17`
  - t7: `-0.002·(0.9990-1.0010)/0.0001 = -0.002·(-20) = +0.04` → cum `-0.13`
- **`total_pips = -0.13`** (last equity), **`max_drawdown = 0.17`** (running peak
  0 minus trough -0.17), **`exposure_sign_flips = 1`**.

The integer-valued `exposure_sign_flips` is pinned exactly; the two f64 metrics
are pinned within `1e-9` (the computation's float dust is ~`1e-15`, so the
tolerance is safe by six orders of magnitude while staying a real correctness
pin). Determinism is pinned exactly (two runs, identical JSON).

---

## Task 1: `aura-std::Recorder` sink node

**Files:**
- Create: `crates/aura-std/src/recorder.rs`
- Modify: `crates/aura-std/src/lib.rs:18-29`
- Test: `crates/aura-std/src/recorder.rs` (inline `#[cfg(test)] mod tests`)

- [ ] **Step 1: Create `crates/aura-std/src/recorder.rs` with the node + its failing tests**

Write the file with exactly this content:

```rust
//! `Recorder` — a reusable recording sink (the glossary *sink* role, C8/C22):
//! a pure consumer that, each fired cycle, sends `(ctx.now(), row)` — the newest
//! value of each declared input column — to an out-of-graph `mpsc` destination it
//! holds. It produces nothing (`output: vec![]`), so it is a leaf in the DAG. The
//! `mpsc::Sender` keeps the engine's purity invariant (C7): the node carries no
//! `Rc`/`RefCell` interior mutability, only an owned channel handle. Supports all
//! four base scalar kinds so any column can be persisted; returns `None` (filters)
//! until every input column is warm.

use aura_core::{Ctx, Firing, InputSpec, Node, NodeSchema, Scalar, ScalarKind, Timestamp};
use std::sync::mpsc::Sender;

/// A recording sink over `kinds.len()` input columns. Each fired cycle it reads
/// the newest value of every column and sends the row to `tx`; it returns `None`
/// (records, forwards nothing) and `None` during warm-up until all columns have a
/// value.
pub struct Recorder {
    kinds: Vec<ScalarKind>,
    firing: Firing,
    tx: Sender<(Timestamp, Vec<Scalar>)>,
}

impl Recorder {
    /// A recorder over one input column per entry in `kinds`, each with the given
    /// `firing` policy, sending recorded `(timestamp, row)` pairs to `tx`.
    pub fn new(kinds: &[ScalarKind], firing: Firing, tx: Sender<(Timestamp, Vec<Scalar>)>) -> Self {
        Self { kinds: kinds.to_vec(), firing, tx }
    }
}

impl Node for Recorder {
    fn schema(&self) -> NodeSchema {
        NodeSchema {
            inputs: self
                .kinds
                .iter()
                .map(|&kind| InputSpec { kind, lookback: 1, firing: self.firing })
                .collect(),
            output: vec![],
        }
    }

    fn eval(&mut self, ctx: Ctx<'_>) -> Option<&[Scalar]> {
        let mut row = Vec::with_capacity(self.kinds.len());
        for (i, &kind) in self.kinds.iter().enumerate() {
            // newest of each column by kind; `?` returns None (warm-up) if cold.
            let scalar = match kind {
                ScalarKind::F64 => Scalar::F64(ctx.f64_in(i).get(0)?),
                ScalarKind::I64 => Scalar::I64(ctx.i64_in(i).get(0)?),
                ScalarKind::Bool => Scalar::Bool(ctx.bool_in(i).get(0)?),
                ScalarKind::Timestamp => Scalar::Ts(ctx.ts_in(i).get(0)?),
            };
            row.push(scalar);
        }
        let _ = self.tx.send((ctx.now(), row));
        None
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use aura_core::{AnyColumn, Timestamp};
    use std::sync::mpsc;

    #[test]
    fn recorder_captures_f64_stream_after_warmup() {
        let (tx, rx) = mpsc::channel();
        let mut rec = Recorder::new(&[ScalarKind::F64], Firing::Any, tx);

        // size the one f64 input column from the schema, as the engine would.
        let schema = rec.schema();
        assert!(schema.output.is_empty(), "a sink declares no output (C8)");
        let mut inputs = vec![AnyColumn::with_capacity(
            schema.inputs[0].kind,
            schema.inputs[0].lookback,
        )];

        // cold: returns None and records nothing.
        assert_eq!(rec.eval(Ctx::new(&inputs, Timestamp(1))), None);
        assert!(rx.try_recv().is_err());

        // warm: returns None (pure consumer) but records (now, [F64(newest)]).
        for (t, v) in [(2_i64, 10.0_f64), (3, 20.0), (4, 30.0)] {
            inputs[0].push(Scalar::F64(v)).unwrap();
            assert_eq!(rec.eval(Ctx::new(&inputs, Timestamp(t))), None);
        }
        let rows: Vec<(Timestamp, Vec<Scalar>)> = rx.try_iter().collect();
        assert_eq!(
            rows,
            vec![
                (Timestamp(2), vec![Scalar::F64(10.0)]),
                (Timestamp(3), vec![Scalar::F64(20.0)]),
                (Timestamp(4), vec![Scalar::F64(30.0)]),
            ]
        );
    }

    #[test]
    fn recorder_is_none_until_all_columns_warm() {
        let (tx, rx) = mpsc::channel();
        let mut rec = Recorder::new(&[ScalarKind::F64, ScalarKind::F64], Firing::Any, tx);
        let mut inputs = vec![
            AnyColumn::with_capacity(ScalarKind::F64, 1),
            AnyColumn::with_capacity(ScalarKind::F64, 1),
        ];

        // only column 0 present -> None, nothing recorded.
        inputs[0].push(Scalar::F64(1.0)).unwrap();
        assert_eq!(rec.eval(Ctx::new(&inputs, Timestamp(1))), None);
        assert!(rx.try_recv().is_err());

        // both present -> records the full row (still returns None).
        inputs[1].push(Scalar::F64(2.0)).unwrap();
        assert_eq!(rec.eval(Ctx::new(&inputs, Timestamp(2))), None);
        let rows: Vec<(Timestamp, Vec<Scalar>)> = rx.try_iter().collect();
        assert_eq!(rows, vec![(Timestamp(2), vec![Scalar::F64(1.0), Scalar::F64(2.0)])]);
    }
}
```

- [ ] **Step 2: Wire the module into `crates/aura-std/src/lib.rs`**

Add `mod recorder;` between `mod lincomb;` (line 20) and `mod sim_broker;`
(line 21); add `pub use recorder::Recorder;` between `pub use lincomb::LinComb;`
(line 26) and `pub use sim_broker::SimBroker;` (line 27). The `mod` block becomes:

```rust
mod add;
mod exposure;
mod lincomb;
mod recorder;
mod sim_broker;
mod sma;
mod sub;
pub use add::Add;
pub use exposure::Exposure;
pub use lincomb::LinComb;
pub use recorder::Recorder;
pub use sim_broker::SimBroker;
pub use sma::Sma;
pub use sub::Sub;
```

- [ ] **Step 3: Run the Recorder tests to verify they pass**

Run: `cargo test -p aura-std recorder`
Expected: PASS — `recorder_captures_f64_stream_after_warmup` and
`recorder_is_none_until_all_columns_warm` both green (2 tests run; the filter
`recorder` matches exactly these two named tests).

- [ ] **Step 4: Verify the crate still lints and docs clean**

Run: `cargo clippy -p aura-std --all-targets -- -D warnings`
Expected: PASS — no warnings.

---

## Task 2: `aura-cli` `run` subcommand

**Files:**
- Modify: `crates/aura-cli/Cargo.toml:12-13`
- Modify: `crates/aura-cli/src/main.rs:1-8`
- Test: `crates/aura-cli/src/main.rs` (inline `#[cfg(test)] mod tests`)

- [ ] **Step 1: Add the path deps to `crates/aura-cli/Cargo.toml`**

Replace the `[dependencies]` block (lines 12-13) with:

```toml
[dependencies]
aura-core = { path = "../aura-core" }
aura-engine = { path = "../aura-engine" }
aura-std = { path = "../aura-std" }
```

- [ ] **Step 2: Replace `crates/aura-cli/src/main.rs` with the run wiring + tests**

Write the file with exactly this content:

```rust
//! `aura` — the programmatic / CLI face of the engine (the surface the LLM and
//! automation drive: author a node, run a sim/sweep, emit structured metrics).
//!
//! The walking skeleton's closing seam: `aura run` bootstraps a built-in sample
//! signal-quality harness (synthetic source → SMA-cross → Exposure → SimBroker →
//! recording sinks), runs it deterministically (C1), and prints the run's
//! metrics + manifest (#6) as canonical JSON to stdout (the headline C14 move).

use aura_core::{Firing, Scalar, ScalarKind, Timestamp};
use aura_engine::{
    f64_field, summarize, Edge, Harness, RunManifest, RunReport, SourceSpec, Target,
};
use aura_std::{Exposure, Recorder, SimBroker, Sma, Sub};
use std::sync::mpsc::{self, Receiver};

/// The built-in synthetic price stream: rises through t=4 then reverses, so the
/// demo trace carries one exposure sign flip and a real drawdown (C22 populated
/// trace). Deterministic and fixed (C1).
fn synthetic_prices() -> Vec<(Timestamp, Scalar)> {
    [
        (1_i64, 1.0000_f64),
        (2, 1.0010),
        (3, 1.0030),
        (4, 1.0060),
        (5, 1.0040),
        (6, 1.0010),
        (7, 0.9990),
    ]
    .iter()
    .map(|&(t, p)| (Timestamp(t), Scalar::F64(p)))
    .collect()
}

/// Bootstrap the sample signal-quality harness with two recording sinks (equity
/// tapped on the SimBroker, exposure tapped on the Exposure node). Rust-authored
/// wiring (C17/C20) over the raw bootstrap API — no builder DSL this cycle. The
/// price taps both SMAs and the broker's price slot (slot 1); exposure feeds the
/// broker's slot 0 (slot order is load-bearing — both are f64).
fn sample_harness() -> (
    Harness,
    Receiver<(Timestamp, Vec<Scalar>)>,
    Receiver<(Timestamp, Vec<Scalar>)>,
) {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let h = Harness::bootstrap(
        vec![
            Box::new(Sma::new(2)),                                          // 0 fast SMA
            Box::new(Sma::new(4)),                                          // 1 slow SMA
            Box::new(Sub::new()),                                           // 2 spread
            Box::new(Exposure::new(0.5)),                                   // 3 exposure
            Box::new(SimBroker::new(0.0001)),                               // 4 sim-optimal broker
            Box::new(Recorder::new(&[ScalarKind::F64], Firing::Any, tx_eq)), // 5 equity sink
            Box::new(Recorder::new(&[ScalarKind::F64], Firing::Any, tx_ex)), // 6 exposure sink
        ],
        vec![SourceSpec {
            kind: ScalarKind::F64,
            targets: vec![
                Target { node: 0, slot: 0 },
                Target { node: 1, slot: 0 },
                Target { node: 4, slot: 1 }, // price into the broker's price slot
            ],
        }],
        vec![
            Edge { from: 0, to: 2, slot: 0, from_field: 0 },
            Edge { from: 1, to: 2, slot: 1, from_field: 0 },
            Edge { from: 2, to: 3, slot: 0, from_field: 0 },
            Edge { from: 3, to: 4, slot: 0, from_field: 0 }, // exposure into broker slot 0
            Edge { from: 4, to: 5, slot: 0, from_field: 0 }, // equity -> sink 5
            Edge { from: 3, to: 6, slot: 0, from_field: 0 }, // exposure -> sink 6
        ],
    )
    .expect("valid sample signal-quality DAG");
    (h, rx_eq, rx_ex)
}

/// Run the sample harness and fold it into a `RunReport` (drain both sinks →
/// `f64_field` → `summarize` → pair with a `RunManifest`). Pure and deterministic
/// (C1): the same build yields the same report.
fn run_sample() -> RunReport {
    let (mut h, rx_eq, rx_ex) = sample_harness();
    let prices = synthetic_prices();
    let window = (
        prices.first().expect("non-empty stream").0,
        prices.last().expect("non-empty stream").0,
    );
    h.run(vec![prices]);

    let eq_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_eq.try_iter().collect();
    let ex_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_ex.try_iter().collect();
    let equity = f64_field(&eq_rows, 0);
    let exposure = f64_field(&ex_rows, 0);
    let metrics = summarize(&equity, &exposure);

    RunReport {
        manifest: RunManifest {
            commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
            params: vec![
                ("sma_fast".to_string(), 2.0),
                ("sma_slow".to_string(), 4.0),
                ("exposure_scale".to_string(), 0.5),
            ],
            window,
            seed: 0,
            broker: "sim-optimal(pip_size=0.0001)".to_string(),
        },
        metrics,
    }
}

fn main() {
    let mut args = std::env::args().skip(1);
    match args.next().as_deref() {
        Some("run") => println!("{}", run_sample().to_json()),
        _ => {
            eprintln!("aura: usage: aura run");
            std::process::exit(2);
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn run_sample_is_deterministic_and_non_trivial() {
        let r1 = run_sample();
        let r2 = run_sample();
        // C1 determinism: two runs are bit-identical (metrics + rendered JSON).
        assert_eq!(r1.metrics, r2.metrics);
        assert_eq!(r1.to_json(), r2.to_json());

        let m = &r1.metrics;
        // exactly one exposure sign flip in the demo trace (rises then reverses).
        assert_eq!(m.exposure_sign_flips, 1);
        // a non-trivial, populated trace: a real drawdown.
        assert!(m.max_drawdown > 0.0);
        // hand-computed magnitudes for the chosen stream (float tolerance; the
        // computation's dust is ~1e-15).
        assert!(
            (m.max_drawdown - 0.17).abs() < 1e-9,
            "max_drawdown = {}",
            m.max_drawdown
        );
        assert!(
            (m.total_pips - (-0.13)).abs() < 1e-9,
            "total_pips = {}",
            m.total_pips
        );

        // manifest carries the sample's known configuration.
        let (from, to) = r1.manifest.window;
        assert_eq!((from.0, to.0), (1, 7));
        assert_eq!(r1.manifest.commit, "unknown");
    }
}
```

- [ ] **Step 3: Run the `run_sample` unit test to verify it passes**

Run: `cargo test -p aura-cli --bin aura run_sample`
Expected: PASS — `run_sample_is_deterministic_and_non_trivial` green (1 test run;
the filter `run_sample` matches that one named test).

- [ ] **Step 4: Smoke-run the binary by hand**

Run: `cargo run -p aura-cli -- run`
Expected: a single-line JSON object on stdout beginning
`{"manifest":{"commit":"unknown","params":{"sma_fast":2,"sma_slow":4,"exposure_scale":0.5},"window":[1,7],"seed":0,"broker":"sim-optimal(pip_size=0.0001)"},"metrics":{"total_pips":` …
ending with `"exposure_sign_flips":1}}`, exit code 0.

Run: `cargo run -p aura-cli 2>&1 >/dev/null`
Expected: `aura: usage: aura run` on stderr; exit code 2.

---

## Task 3: `aura-cli` CLI integration test

**Files:**
- Create: `crates/aura-cli/tests/cli_run.rs`

- [ ] **Step 1: Create `crates/aura-cli/tests/cli_run.rs` with the binary-driving tests**

Write the file with exactly this content:

```rust
//! Integration test: drive the built `aura` binary as a downstream user would,
//! asserting the `run` subcommand's stdout/exit contract and the bad-args path.

use std::process::Command;

/// Path to the freshly-built `aura` binary (Cargo sets this env var for the test
/// crate; the binary is named `aura` in `Cargo.toml`).
const BIN: &str = env!("CARGO_BIN_EXE_aura");

#[test]
fn run_prints_json_and_exits_zero() {
    let out = Command::new(BIN).arg("run").output().expect("spawn aura run");
    assert!(out.status.success(), "exit status: {:?}", out.status);

    let stdout = String::from_utf8(out.stdout).expect("utf-8 stdout");
    // exactly one line (the JSON object + a trailing newline from println!).
    assert_eq!(stdout.lines().count(), 1, "stdout was: {stdout:?}");
    let line = stdout.trim_end();

    // canonical cycle-0009 JSON shape: nested manifest + metrics, stable keys.
    assert!(line.starts_with("{\"manifest\":{\"commit\":\"unknown\","), "got: {line}");
    assert!(line.contains("\"broker\":\"sim-optimal(pip_size=0.0001)\""), "got: {line}");
    assert!(line.contains("\"window\":[1,7]"), "got: {line}");
    assert!(line.contains("\"metrics\":{\"total_pips\":"), "got: {line}");
    // the integer sign-flip count is stable across float renderings.
    assert!(line.ends_with("\"exposure_sign_flips\":1}}"), "got: {line}");
}

#[test]
fn no_args_prints_usage_and_exits_two() {
    let out = Command::new(BIN).output().expect("spawn aura");
    assert_eq!(out.status.code(), Some(2), "exit status: {:?}", out.status);
    assert!(out.stdout.is_empty(), "stdout should be empty on the usage path");
    let stderr = String::from_utf8(out.stderr).expect("utf-8 stderr");
    assert!(stderr.contains("usage"), "stderr was: {stderr:?}");
}
```

- [ ] **Step 2: Run the integration test to verify it passes**

Run: `cargo test -p aura-cli --test cli_run`
Expected: PASS — `run_prints_json_and_exits_zero` and
`no_args_prints_usage_and_exits_two` both green (2 tests run; the `--test cli_run`
target resolves to the file created in Step 1).

---

## Task 4: Full-workspace gates

**Files:** none (verification only).

- [ ] **Step 1: Full test suite**

Run: `cargo test --workspace`
Expected: PASS — all pre-existing tests plus the new Recorder (2), `run_sample`
(1), and `cli_run` (2) tests green; 0 failures.

- [ ] **Step 2: Lint gate**

Run: `cargo clippy --workspace --all-targets -- -D warnings`
Expected: PASS — no warnings across the workspace.

- [ ] **Step 3: Doc gate**

Run: `RUSTDOCFLAGS="-D warnings" cargo doc --workspace --no-deps`
Expected: PASS — docs build with no warnings (the new `Recorder` rustdoc and the
`aura-cli` module/fn docs included).

---

## Self-review (planner Step 5)

1. **Spec coverage:** Recorder node (spec §Architecture 1, Components) → Task 1;
   `synthetic_prices`/`sample_harness`/`run_sample`/`main` (§Architecture 2,
   Components, Data flow, Error handling) → Task 2; CLI integration test (§Testing
   strategy) → Task 3; the three gates (§Testing strategy) → Task 4. The
   user-facing invocation/output (§Concrete code shapes) is exercised by Task 2
   Step 4 + Task 3. All spec sections covered.
2. **Placeholder scan:** no "TBD"/"TODO"/"similar to"/"implement later"/"add
   appropriate" — every code body is verbatim.
3. **Type consistency:** `Recorder` / `Recorder::new(kinds, firing, tx)` /
   `RunReport` / `RunManifest` / `summarize` / `f64_field` / `Harness::bootstrap`
   / `Edge`/`Target`/`SourceSpec` / `Sma`/`Sub`/`Exposure`/`SimBroker` match the
   recon'd signatures and are spelled identically across tasks. `Scalar::Ts` (not
   `Scalar::Timestamp`) used for the `ScalarKind::Timestamp` arm. The aura-std
   `pub use` list stays alphabetical.
4. **Step granularity:** each step is one file write / one wiring edit / one
   command — 2-5 minutes each.
5. **No commit steps:** none present; the orchestrator commits.
6. **Pin/replacement substring contiguity:** the integration test's
   `line.starts_with("{\"manifest\":{\"commit\":\"unknown\",")` and
   `line.ends_with("\"exposure_sign_flips\":1}}")` are substrings the cycle-0009
   `to_json` produces verbatim (manifest-first nesting, `commit` first field,
   `exposure_sign_flips` last metric); `"window":[1,7]` is the `(Timestamp(1),
   Timestamp(7))` rendering (window-as-2-array, documented schema). No soft-wrap
   splits any pinned substring.
7. **Compile-gate vs. deferred-caller ordering:** no signature change — the work
   is pure-additive (a new module + a new binary body + a new dep). Task 2 Step 1
   adds the `aura-std`/`aura-core` deps *before* Step 2 introduces the `use`
   statements that need them, so each task compiles at its own boundary; Task 1
   (the `Recorder` it imports) precedes Task 2. No deferred caller.
8. **Verification-command filter strings resolve:** `cargo test -p aura-std
   recorder` matches the two `recorder_*` tests named in Task 1; `cargo test -p
   aura-cli --bin aura run_sample` matches the `run_sample_*` test named in Task 2;
   `cargo test -p aura-cli --test cli_run` targets the file created in Task 3.
   Each filter/target is verified against a real named test/file in this plan, not
   guessed from a feature word. Task 4 runs the unfiltered workspace suite with an
   explicit "0 failures / new counts" expectation.
9. **Parse-the-bytes-you-inline gate:** the profile declares no `spec_validation`
   parser, so the gate is a documented no-op for this plan's non-Rust fenced
   blocks (one `text` price table, the `toml` dep block, the bash Run commands);
   the Rust bodies are validated by the `implement` compile gate (Tasks 1-4 build
   commands). No surface-language (non-Rust) program is inlined that a configured
   parser would own.
