From bb8045ea5932280f02bcd42684cc615d34d774af Mon Sep 17 00:00:00 2001
From: Brummel <mould@mycelium.de>
Date: Fri, 19 Jun 2026 18:23:42 +0200
Subject: [PATCH] =?UTF-8?q?plan:=20trace-chart=20viewer=20Tier-1=20?=
 =?UTF-8?q?=E2=80=94=20ordinal=20x-axis=20+=20zoom/pan/cursor-sync?=
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Five tasks: RED x-mode guard; buildCharts gains xMode (ordinal default) +
wheelZoomPlugin + panel cursor-sync, with the two twin guards re-pointed in
lockstep; mount render(xMode)+toggle; render.rs CHART_HEAD toggle + chart-only
style + chrome tests; full-suite/clippy/e2e gate.

refs #103
---
 docs/plans/0057-trace-chart-viewer-tier1.md | 528 ++++++++++++++++++++
 1 file changed, 528 insertions(+)
 create mode 100644 docs/plans/0057-trace-chart-viewer-tier1.md

diff --git a/docs/plans/0057-trace-chart-viewer-tier1.md b/docs/plans/0057-trace-chart-viewer-tier1.md
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+# Trace-chart viewer Tier-1 (ordinal x-axis + zoom/pan/cursor-sync) — Implementation Plan
+
+> **Parent spec:** `docs/specs/0057-trace-chart-viewer-tier1.md`
+>
+> **For agentic workers:** REQUIRED SUB-SKILL: use the `implement` skill to run
+> this plan. Steps use `- [ ]` checkboxes for tracking.
+
+**Goal:** Make the served trace chart's x-axis ordinal (gap-collapsed) by default with a
+one-click continuous toggle, and add wheel-zoom / drag-pan / dblclick-reset, a
+value-readout legend, and panel cursor-sync — confined to the read/render side.
+
+**Architecture:** The whole feature lives in `crates/aura-cli/assets/chart-viewer.js`
+(the pure `buildCharts` gains an `xMode` param + a `wheelZoomPlugin` factory; the
+browser-only `mount` gains a `render(xMode)` teardown/rebuild wired to a header toggle)
+and `crates/aura-cli/src/render.rs` (`CHART_HEAD` gains the toggle button; a chart-only
+`<style>` is injected by `render_chart_html`). The Rust serve contract
+(`build_chart_data`, the injected `window.AURA_TRACES = {mode, xs, series}`,
+`ColumnarTrace`/`TraceStore`) is unchanged.
+
+**Tech Stack:** vendored uPlot 1.6.32 (IIFE global); pure JS `buildCharts` driven by
+headless `node` guards; Rust `render_chart_html` string assembly + inline `#[cfg(test)]`
+tests.
+
+---
+
+## Files this plan creates or modifies
+
+- Create: `crates/aura-cli/tests/chart_viewer_xmode.mjs` — headless guard: default-ordinal
+  `data[0]` index spine, `"continuous"` ⇒ `data[0] === xs`, panel `cursor.sync.key`
+  equality, `opts.plugins[0].hooks.init` present.
+- Create: `crates/aura-cli/tests/chart_viewer_xmode.rs` — Rust build-guard shell mirroring
+  `chart_viewer.rs` (shells `node` at `tests/chart_viewer_xmode.mjs`); auto-discovered.
+- Modify: `crates/aura-cli/assets/chart-viewer.js:7-61` — add `wheelZoomPlugin`; rewrite
+  `buildCharts` (lines 12-40) with `xMode`; rewrite `mount` (lines 43-54).
+- Modify: `crates/aura-cli/src/render.rs:63-69` (`CHART_HEAD` toggle button), `:75-77`
+  (add `CHART_CSS` const), `:136-163` (`render_chart_html` injects `CHART_CSS`),
+  `:175-250` (inline tests: assert `xmode-toggle` present on the chart page, absent on the
+  graph page).
+- Test: `crates/aura-cli/tests/chart_viewer_build.mjs:32-46` — re-point the two
+  `data[0] === xs` assertions to the ordinal index spine; add an explicit `"continuous"`
+  check.
+- Test: `crates/aura-cli/tests/chart_viewer_gaps.mjs:32-46` — re-point the two
+  `data[0] === xs` assertions to the ordinal index spine; the null-gap assertions on
+  `data[1..]` stay unchanged.
+- Fixtures (read-only, not modified): `crates/aura-cli/tests/fixtures/sample-traces.json`
+  (`xs:[1,2,3]`, 2 series), `crates/aura-cli/tests/fixtures/sparse-traces.json`
+  (`xs:[1,2,3,4]`, 2 series with null gaps).
+
+---
+
+## Task 1: New RED guard — x-mode / sync / interaction-plugin
+
+**Files:**
+- Create: `crates/aura-cli/tests/chart_viewer_xmode.mjs`
+- Create: `crates/aura-cli/tests/chart_viewer_xmode.rs`
+
+- [ ] **Step 1: Write the failing node guard**
+
+Create `crates/aura-cli/tests/chart_viewer_xmode.mjs`:
+
+```js
+// Headless guard for the trace-chart viewer's x-mode + interaction wiring.
+// Properties: (1) the DEFAULT x spine is ORDINAL — data[0] is [0..n-1], not the raw
+// timestamps, so non-trading gaps collapse; the x-axis carries an index->label values
+// formatter. (2) "continuous" mode restores data[0] === xs verbatim. (3) panels carry a
+// shared cursor.sync.key so the crosshair lines up. (4) every config attaches an
+// interaction plugin with an init hook. Drives the pure buildCharts; no DOM/uPlot.
+import { createRequire } from "node:module";
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+
+const require = createRequire(import.meta.url);
+const here = dirname(fileURLToPath(import.meta.url));
+const traces = JSON.parse(readFileSync(join(here, "fixtures", "sample-traces.json"), "utf8"));
+
+const fail = (msg) => { console.error("FAIL: " + msg); process.exit(1); };
+const sameArr = (a, b, msg) => {
+  if (!Array.isArray(a) || !Array.isArray(b) || a.length !== b.length || a.some((v, i) => v !== b[i])) fail(msg);
+};
+
+global.window = { AURA_TRACES: traces };
+const { buildCharts } = require(join(here, "..", "assets", "chart-viewer.js"));
+
+const n = traces.xs.length;
+const idx = Array.from({ length: n }, (_, i) => i);
+
+// (1) default is ordinal: data[0] is the index spine, with an x-axis values formatter.
+const ov = buildCharts(traces, "overlay");
+sameArr(ov[0].data[0], idx, "default overlay x is the ordinal index spine [0..n-1]");
+if (typeof ov[0].opts.axes[0].values !== "function") fail("ordinal overlay x-axis lacks a values formatter");
+
+// (4) interaction wired: a plugin with an init hook.
+if (!Array.isArray(ov[0].opts.plugins) || ov[0].opts.plugins.length < 1) fail("no interaction plugin attached");
+if (typeof ov[0].opts.plugins[0].hooks.init !== "function") fail("interaction plugin has no init hook");
+
+// (2) continuous mode: data[0] is xs verbatim.
+const ovc = buildCharts(traces, "overlay", "continuous");
+sameArr(ovc[0].data[0], traces.xs, "continuous overlay x is xs verbatim");
+
+// (3) panels: cursor.sync.key present and equal across panels; default still ordinal.
+const panels = buildCharts(traces, "panels");
+const keys = panels.map((p) => p.opts.cursor && p.opts.cursor.sync && p.opts.cursor.sync.key);
+if (keys.some((k) => !k)) fail("a panel lacks cursor.sync.key");
+if (new Set(keys).size !== 1) fail("panels do not share one cursor.sync key");
+sameArr(panels[0].data[0], idx, "default panel x is the ordinal index spine");
+
+console.log("OK — ordinal default + continuous toggle + panel cursor-sync + interaction plugin.");
+process.exit(0);
+```
+
+- [ ] **Step 2: Write the Rust build-guard shell**
+
+Create `crates/aura-cli/tests/chart_viewer_xmode.rs`:
+
+```rust
+//! Integration guard for the `aura chart` viewer's x-mode (ordinal default + continuous
+//! toggle), panel cursor-sync, and interaction-plugin wiring. These live in
+//! `chart-viewer.js` and cannot be checked from Rust; this shells out to `node`, running
+//! `tests/chart_viewer_xmode.mjs`, which drives the pure `buildCharts`. `node` is
+//! REQUIRED: if absent this test FAILS.
+
+use std::path::PathBuf;
+use std::process::Command;
+
+#[test]
+fn chart_viewer_ordinal_default_continuous_toggle_and_sync() {
+    let script = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .join("tests")
+        .join("chart_viewer_xmode.mjs");
+    assert!(script.exists(), "guard script missing at {}", script.display());
+
+    let out = match Command::new("node").arg(&script).output() {
+        Ok(out) => out,
+        Err(e) => panic!(
+            "node is required for the chart-viewer x-mode guard but could not be run \
+             ({e}); install Node.js or ensure `node` is on PATH"
+        ),
+    };
+
+    let stdout = String::from_utf8_lossy(&out.stdout);
+    let stderr = String::from_utf8_lossy(&out.stderr);
+    assert!(
+        out.status.success(),
+        "chart-viewer x-mode guard failed (exit {:?}).\n--- node stdout ---\n{stdout}\n--- node stderr ---\n{stderr}",
+        out.status.code()
+    );
+}
+```
+
+- [ ] **Step 3: Run the new guard to verify it FAILS against current code**
+
+Run: `cargo test -p aura-cli --test chart_viewer_xmode`
+Expected: FAIL — the node guard prints `FAIL: default overlay x is the ordinal index
+spine [0..n-1]` (today `buildCharts` ignores the 3rd arg and sets `data[0] = xs`, i.e.
+`[1,2,3]`, not `[0,1,2]`), node exits 1, the Rust assertion panics with
+`chart-viewer x-mode guard failed`.
+
+---
+
+## Task 2: `buildCharts` — `xMode` + ordinal default + sync + plugin (and re-point the twin guards)
+
+**Files:**
+- Modify: `crates/aura-cli/assets/chart-viewer.js:7-40`
+- Test: `crates/aura-cli/tests/chart_viewer_build.mjs:32-46`
+- Test: `crates/aura-cli/tests/chart_viewer_gaps.mjs:32-46`
+
+- [ ] **Step 1: Add `wheelZoomPlugin` and rewrite `buildCharts`**
+
+In `crates/aura-cli/assets/chart-viewer.js`, replace the current `buildCharts` function
+(lines 12-40) with the `wheelZoomPlugin` factory followed by the new `buildCharts`. The
+`PALETTE` declaration (line 7) and the leading comment block stay; `mount` (Task 3) and
+the bootstrap/exports (lines 56-61) stay for now. New text:
+
+```js
+  // wheelZoomPlugin: a pure factory (safe to construct headless — its hooks run only in
+  // a browser). On init it wires wheel-zoom (x, cursor-anchored), drag-pan, and
+  // dblclick-reset onto u.over. uPlot's default drag-box-zoom is disabled in buildCharts
+  // (cursor.drag off) so drag pans instead.
+  function wheelZoomPlugin() {
+    var ZOOM = 0.9; // one wheel notch shrinks/grows the visible x-range by this factor
+    return { hooks: { init: function (u) {
+      var over = u.over;
+      over.addEventListener("wheel", function (e) {
+        e.preventDefault();
+        var rect = over.getBoundingClientRect();
+        var xVal = u.posToVal(e.clientX - rect.left, "x");
+        var lo = u.scales.x.min, hi = u.scales.x.max;
+        var f = e.deltaY < 0 ? ZOOM : 1 / ZOOM; // wheel up = zoom in
+        u.setScale("x", { min: xVal - (xVal - lo) * f, max: xVal + (hi - xVal) * f });
+      }, { passive: false });
+      over.addEventListener("mousedown", function (d) {
+        if (d.button !== 0) return;
+        var x0 = d.clientX, lo = u.scales.x.min, hi = u.scales.x.max;
+        var unitsPerPx = (hi - lo) / over.clientWidth;
+        function move(m) {
+          var dx = (m.clientX - x0) * unitsPerPx;
+          u.setScale("x", { min: lo - dx, max: hi - dx });
+        }
+        function up() {
+          document.removeEventListener("mousemove", move);
+          document.removeEventListener("mouseup", up);
+        }
+        document.addEventListener("mousemove", move);
+        document.addEventListener("mouseup", up);
+      });
+      over.addEventListener("dblclick", function () {
+        u.setScale("x", { min: u.data[0][0], max: u.data[0][u.data[0].length - 1] });
+      });
+    } } };
+  }
+
+  // {xs, series:[{name, y_scale_id, points}]} + mode + xMode -> array of {opts, data}.
+  // xMode in {"ordinal","continuous"}, default "ordinal". ordinal: data[0] is the index
+  // spine [0..n-1] (gaps collapse) and the x-axis/legend map an index back to the real
+  // xs[i]; continuous: data[0] is xs. series points (data[1..]) are untouched either way
+  // (null gaps preserved verbatim). overlay -> one chart; panels -> one chart per series,
+  // sharing a cursor.sync key so the crosshair lines up.
+  function buildCharts(traces, mode, xMode) {
+    xMode = xMode || "ordinal";
+    var xs = traces.xs;
+    var n = xs.length;
+    var idx = [];
+    for (var k = 0; k < n; k++) idx.push(k);
+    var ordinal = xMode !== "continuous";
+    var xData = ordinal ? idx : xs;
+
+    // map an x-position to its real-timestamp label (total; no epoch assumption):
+    // ordinal -> position is an index -> xs[round(pos)]; continuous -> position IS the ts.
+    function xLabel(pos) {
+      if (!ordinal) return String(pos);
+      var j = Math.max(0, Math.min(n - 1, Math.round(pos)));
+      return String(xs[j]);
+    }
+    function xAxisCfg() { return ordinal ? { values: function (u, splits) { return splits.map(xLabel); } } : {}; }
+    function xSeriesCfg() { return { value: function (u, v) { return v == null ? "--" : xLabel(v); } }; }
+
+    if (mode === "panels") {
+      var SYNC = "aura-x"; // shared key -> crosshair sync across panels
+      return traces.series.map(function (s, i) {
+        return {
+          opts: {
+            title: s.name,
+            scales: { x: { time: false }, [s.y_scale_id]: {} },
+            series: [xSeriesCfg(), { label: s.name, scale: s.y_scale_id, stroke: PALETTE[i % PALETTE.length] }],
+            axes: [xAxisCfg(), { scale: s.y_scale_id }],
+            cursor: { sync: { key: SYNC }, drag: { x: false, y: false } },
+            plugins: [wheelZoomPlugin()],
+          },
+          data: [xData, s.points],
+        };
+      });
+    }
+
+    // overlay (default)
+    var scales = { x: { time: false } };
+    var uSeries = [xSeriesCfg()];
+    var axes = [xAxisCfg()];
+    traces.series.forEach(function (s, i) {
+      scales[s.y_scale_id] = {};
+      uSeries.push({ label: s.name, scale: s.y_scale_id, stroke: PALETTE[i % PALETTE.length] });
+      // the first two series carry a drawn axis (left, then right); the rest keep their
+      // own auto-scale, read via the legend.
+      if (i < 2) axes.push({ scale: s.y_scale_id, side: i === 0 ? 3 : 1 });
+    });
+    return [{
+      opts: { scales: scales, series: uSeries, axes: axes, cursor: { drag: { x: false, y: false } }, plugins: [wheelZoomPlugin()] },
+      data: [xData].concat(traces.series.map(function (s) { return s.points; })),
+    }];
+  }
+```
+
+- [ ] **Step 2: Re-point the build guard for the ordinal default**
+
+In `crates/aura-cli/tests/chart_viewer_build.mjs`, the default `buildCharts(traces,
+"overlay")` now yields an ordinal `data[0]`. Add an index spine and re-point the two
+`data[0] === xs` assertions; add an explicit continuous check. Replace lines 29-46 (from
+`const n = traces.series.length;` through the panels loop) with:
+
+```js
+const n = traces.series.length;
+const idx = Array.from({ length: traces.xs.length }, (_, i) => i);
+
+// overlay: ONE chart, all series superimposed, each on its own scale. Default x spine is
+// ORDINAL (indices) so non-trading gaps collapse.
+const overlay = buildCharts(traces, "overlay");
+eq(overlay.length, 1, "overlay is one chart");
+eq(overlay[0].data.length, 1 + n, "overlay data = xs + N series");
+eq(overlay[0].opts.series.length, 1 + n, "overlay uPlot series = x + N");
+sameArr(overlay[0].data[0], idx, "default overlay x-axis is the ordinal index spine");
+const scaleIds = overlay[0].opts.series.slice(1).map((s) => s.scale);
+eq(new Set(scaleIds).size, n, "each overlay series has a distinct y-scale");
+
+// continuous mode restores the real-timestamp x spine.
+const overlayC = buildCharts(traces, "overlay", "continuous");
+sameArr(overlayC[0].data[0], traces.xs, "continuous overlay x-axis is the shared xs");
+
+// panels: ONE chart per series, all positionally aligned on the SAME ordinal spine.
+const panels = buildCharts(traces, "panels");
+eq(panels.length, n, "panels = one chart per series");
+for (const p of panels) {
+  eq(p.data.length, 2, "each panel = xs + its one series");
+  sameArr(p.data[0], idx, "panel shares the same ordinal index spine (position-aligned)");
+}
+```
+
+- [ ] **Step 3: Re-point the gaps guard for the ordinal default**
+
+In `crates/aura-cli/tests/chart_viewer_gaps.mjs`, re-point only the two `data[0] === xs`
+assertions (lines 37 and 43); the null-gap assertions on `data[1..]` (lines 38-39, 44-45)
+stay byte-for-byte. Replace lines 32-45 (from `const eqPoints` through the panel-1
+assertion) with:
+
+```js
+const eqPoints = traces.series[0].points;   // [0.0, 0.001, null, 0.004]
+const exPoints = traces.series[1].points;   // [1.0, null, null, -1.0]
+const idx = Array.from({ length: traces.xs.length }, (_, i) => i);
+
+// overlay: the data array is [ordinal spine, ...each series' points], nulls preserved.
+const overlay = buildCharts(traces, "overlay")[0];
+sameArr(overlay.data[0], idx, "overlay x is the ordinal index spine (gaps collapsed)");
+sameArr(overlay.data[1], eqPoints, "overlay equity points carry their null gap verbatim");
+sameArr(overlay.data[2], exPoints, "overlay exposure points carry their null gaps verbatim");
+
+// panels: each panel is [ordinal spine, its own series' points] — same nulls.
+const panels = buildCharts(traces, "panels");
+sameArr(panels[0].data[0], idx, "panel 0 shares the ordinal index spine");
+sameArr(panels[0].data[1], eqPoints, "panel 0 carries equity's null gap verbatim");
+sameArr(panels[1].data[1], exPoints, "panel 1 carries exposure's null gaps verbatim");
+```
+
+- [ ] **Step 4: Run the new guard — now PASSES**
+
+Run: `cargo test -p aura-cli --test chart_viewer_xmode`
+Expected: PASS — node prints `OK — ordinal default + continuous toggle + panel
+cursor-sync + interaction plugin.`
+
+- [ ] **Step 5: Run the re-pointed build guard**
+
+Run: `cargo test -p aura-cli --test chart_viewer`
+Expected: PASS — node prints `OK — overlay 1 chart / 2 series, panels 2 charts, shared
+xs.` (the build guard's existing success line; structural assertions unchanged).
+
+- [ ] **Step 6: Run the re-pointed gaps guard**
+
+Run: `cargo test -p aura-cli --test chart_viewer_gaps`
+Expected: PASS — node prints `OK — null gaps preserved verbatim across overlay + panels,
+shared union xs.`
+
+---
+
+## Task 3: `mount` — re-render on toggle (browser-only)
+
+**Files:**
+- Modify: `crates/aura-cli/assets/chart-viewer.js:43-54`
+
+- [ ] **Step 1: Rewrite `mount` for a toggle-driven re-render**
+
+In `crates/aura-cli/assets/chart-viewer.js`, replace the current `mount` function (lines
+43-54) with:
+
+```js
+  // Browser-only: instantiate the vendored global uPlot per config into #stage, and wire
+  // the header #xmode-toggle to flip the x spine (ordinal <-> continuous) and re-render.
+  function mount() {
+    var traces = window.AURA_TRACES;
+    var stage = document.getElementById("stage");
+    var toggle = document.getElementById("xmode-toggle");
+    var xMode = "ordinal";
+    var insts = [];
+    function render() {
+      insts.forEach(function (u) { u.destroy(); });
+      insts = [];
+      stage.innerHTML = "";
+      var configs = buildCharts(traces, traces.mode, xMode);
+      var w = stage.clientWidth || 900;
+      var h = configs.length > 1 ? Math.max(160, Math.floor(440 / configs.length)) : 460;
+      configs.forEach(function (cfg) {
+        // eslint-disable-next-line no-undef
+        insts.push(new uPlot(Object.assign({ width: w, height: h }, cfg.opts), cfg.data, stage));
+      });
+      if (toggle) toggle.textContent = xMode === "ordinal" ? "x: collapsed (gaps off)" : "x: continuous (real time)";
+    }
+    if (toggle) toggle.addEventListener("click", function () {
+      xMode = xMode === "ordinal" ? "continuous" : "ordinal";
+      render();
+    });
+    render();
+  }
+```
+
+- [ ] **Step 2: Build the CLI to confirm the asset still compiles in**
+
+`chart-viewer.js` is `include_str!`'d into the binary; `mount` is browser-only and not
+exercised by the node guards. Confirm the crate builds (the asset string is embedded):
+
+Run: `cargo build -p aura-cli`
+Expected: clean build, exit 0.
+
+- [ ] **Step 3: Re-run all three node guards to confirm no regression**
+
+Run: `cargo test -p aura-cli --test chart_viewer_xmode`
+Expected: PASS (mount changes do not touch the pure `buildCharts`).
+
+---
+
+## Task 4: `render.rs` — toggle button + chart-only style + chrome tests
+
+**Files:**
+- Modify: `crates/aura-cli/src/render.rs:63-69` (`CHART_HEAD`), `:75-77` (new `CHART_CSS`),
+  `:136-163` (`render_chart_html`), `:175-250` (inline tests)
+
+- [ ] **Step 1: Add the toggle button to `CHART_HEAD`**
+
+In `crates/aura-cli/src/render.rs`, replace the `CHART_HEAD` const (lines 63-69) with:
+
+```rust
+/// The chart page's `<title>` text and `<header>` line — describes what the chart
+/// view actually renders (timestamp-aligned trace series), not the graph viewer. The
+/// `#xmode-toggle` button is wired by `chart-viewer.js` (`mount`) to flip the x-axis
+/// between the ordinal (gap-collapsed) default and continuous (real-time) spacing.
+const CHART_HEAD: &str = r#"<header>
+  <b>aura chart</b>
+  <span class="sub">timestamp-aligned trace series</span>
+  <button id="xmode-toggle" type="button">x: collapsed (gaps off)</button>
+</header>
+<div id="stage"></div>
+<pre id="err"></pre>
+"#;
+```
+
+- [ ] **Step 2: Add the chart-only `CHART_CSS` const**
+
+In `crates/aura-cli/src/render.rs`, immediately after the `CHART_VIEWER_JS` const (line
+77), add:
+
+```rust
+/// Chart-page-only styling (the `#xmode-toggle` button) — injected by
+/// `render_chart_html` after the vendored uPlot CSS, NOT into the shared `SHELL_HEAD`
+/// (the graph page has no toggle and must not inherit its rule).
+const CHART_CSS: &str = r#"
+#xmode-toggle { margin-left: auto; background: #1e1e2e; color: #cdd6f4;
+  border: 1px solid #313244; border-radius: 6px; padding: 4px 10px;
+  font-family: ui-monospace, monospace; font-size: 12px; cursor: pointer; }
+#xmode-toggle:hover { border-color: #89b4fa; color: #f5e0dc; }
+"#;
+```
+
+- [ ] **Step 3: Inject `CHART_CSS` in `render_chart_html`**
+
+In `crates/aura-cli/src/render.rs` `render_chart_html`, the style block currently pushes
+only `UPLOT_CSS` (around lines 153-155):
+
+```rust
+    html.push_str("<style>");
+    html.push_str(UPLOT_CSS);
+    html.push_str("</style>\n<script>");
+```
+
+Replace it with (append `CHART_CSS` inside the same `<style>`):
+
+```rust
+    html.push_str("<style>");
+    html.push_str(UPLOT_CSS);
+    html.push_str(CHART_CSS);
+    html.push_str("</style>\n<script>");
+```
+
+And extend the `String::with_capacity` hint (around lines 148-150) to include
+`CHART_CSS.len()`:
+
+```rust
+    let mut html = String::with_capacity(
+        SHELL_HEAD.len() + CHART_HEAD.len() + UPLOT_JS.len() + UPLOT_CSS.len() + CHART_CSS.len() + CHART_VIEWER_JS.len() + traces.len() + 256,
+    );
+```
+
+- [ ] **Step 4: Assert the toggle is present on the chart page**
+
+In `crates/aura-cli/src/render.rs`, the test `render_chart_html_wears_its_own_chart_label`
+(lines 228-235) asserts the chart chrome. Add a toggle-present assertion. After the
+existing `assert!(html.contains("<b>aura chart</b>"), ...)` line, insert:
+
+```rust
+        // the x-axis toggle control is part of the chart chrome
+        assert!(html.contains("id=\"xmode-toggle\""), "x-axis toggle control missing from the chart page");
+```
+
+- [ ] **Step 5: Assert the toggle does NOT leak onto the graph page**
+
+In `crates/aura-cli/src/render.rs`, the test
+`render_html_is_self_contained_and_embeds_the_model` (lines 176-197) renders the graph
+page. Before its closing brace, add:
+
+```rust
+        // the chart-only toggle control must not leak onto the graph page
+        assert!(!html.contains("xmode-toggle"), "chart toggle leaked onto the graph page");
+```
+
+- [ ] **Step 6: Run the render inline tests**
+
+Run: `cargo test -p aura-cli --lib render`
+Expected: PASS — all `render_chart_html_*` and `render_html_*` tests green, including the
+two new assertions.
+
+---
+
+## Task 5: Full-suite + clippy + e2e gate
+
+**Files:** none (verification only)
+
+- [ ] **Step 1: Full workspace test suite**
+
+Run: `cargo test --workspace`
+Expected: PASS — all tests green, including the new `chart_viewer_xmode` guard, the
+re-pointed `chart_viewer` / `chart_viewer_gaps` guards, and the render inline tests.
+
+- [ ] **Step 2: Clippy with warnings-as-errors**
+
+Run: `cargo clippy --workspace --all-targets -- -D warnings`
+Expected: exit 0, no warnings.
+
+- [ ] **Step 3: Real e2e — persist then chart, confirm ordinal default + toggle in the page**
+
+Run: `cargo run -q -p aura-cli -- run --trace demo && cargo run -q -p aura-cli -- chart demo > /tmp/demo-chart.html && grep -c 'id="xmode-toggle"' /tmp/demo-chart.html && grep -c 'x: collapsed (gaps off)' /tmp/demo-chart.html`
+Expected: both `grep -c` print `1` — the served page carries the toggle control and its
+default "collapsed" label. (`aura run --trace demo` writes `runs/traces/demo/`; `aura
+chart demo` emits the self-contained page to stdout.)