style: palette swatch → (domain-hue redesign 2026-05-21)

Sidebar swatch now follows function family rather than S88 level, so the
palette is visually identifiable instead of monochromatically blue. Editor-group
rectangles in flow.json still follow S88 — only the registerType color changed.
Full table + rationale: superproject .claude/rules/node-red-flow-layout.md §10.0
and .claude/refactor/OPEN_QUESTIONS.md (2026-05-21 entry).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CONTRACT.md

@@ -3,6 +3,28 @@
 Hand-maintained for Phase 6; the `## Inputs` table is generated from
 `src/commands/index.js` (see Phase 9 generator). Keep ≤ 80 lines.
 
+## Unit convention — approved exception to the canonical-unit rule
+
+EVOLV's canonical units (`CLAUDE.md`, `generalFunctions/CONTRACT.md`)
+are Pa / m³/s / W / K. **reactor diverges deliberately** — it follows
+the ASM (Activated Sludge Model) kinetics literature convention:
+
+- Concentrations: `mg/L` (= g/m³), `mmol/L` for alkalinity.
+- Flow internally: `m³/d` (engine integrator runs in days; see
+  `baseEngine.js` line 40 — `timeStep` config field is seconds, but the
+  internal time base is days).
+- Temperature: `°C`.
+- KLa: `1/h` per the schema; multiplied by the seconds-input `timeStep`
+  inside `_calcOTR` — readers verifying the math should account for the
+  day-internal time base.
+
+Unit conversion at the parent/child boundary happens via
+`MeasurementContainer.UnitPolicy` and the `convert` utility. Other
+nodes (rotatingMachine, pumpingStation, …) honour canonical units;
+reactor is the only ASM-modelled node and pays the small cost of
+domain-textbook units to stay aligned with every published reactor
+reference.
+
 ## Inputs (msg.topic on Port 0)
 
 | Canonical | Aliases (deprecated) | Payload | Effect |

reactor.html

@@ -13,7 +13,7 @@
 <script type="text/javascript">
     RED.nodes.registerType("reactor", {
         category: "EVOLV",
-        color: "#50a8d9",
+        color: "#6FAE5F",
         defaults: {
             name: { value: "" },
             reactor_type: { value: "CSTR", required: true },
@@ -35,7 +35,7 @@
             X_S_init: { value: 75., required: true },
             X_H_init: { value: 30., required: true },
             X_STO_init: { value: 0., required: true },
-            X_A_init: { value: 0.001, required: true },
+            X_A_init: { value: 200, required: true },
             X_TS_init: { value: 125.0009, required: true },
 
             timeStep: { value: 1, required: true },
@@ -267,7 +267,8 @@
         <label for="node-input-dbaseOutputFormat"><i class="fa fa-database"></i> Database Output</label>
         <select id="node-input-dbaseOutputFormat" style="width:60%;">
             <option value="influxdb">influxdb</option>
-            <option value="json">json</option>
+            <option value="frost">frost</option>
+      <option value="json">json</option>
             <option value="csv">csv</option>
         </select>
     </div>

test/basic/timestep-units.basic.test.js

@@ -0,0 +1,44 @@
+'use strict';
+
+// Locks in the contract that `config.timeStep` is interpreted as SECONDS by
+// the reactor kinetics engine. Before 2026-05-19 the schema labelled the field
+// `unit: "h"` while reactor.html labelled it `[s]` and baseEngine divided by
+// 86400 (seconds-per-day) to convert to internal days. A 0.001 schema default
+// — read as hours — would have produced a 3.6 s step; read as seconds it is a
+// 1 ms step. The fix aligned the schema to seconds. This test prevents the
+// drift from reappearing.
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const { Reactor_CSTR } = require('../../src/specificClass');
+const { makeReactorConfig } = require('../helpers/factories');
+
+const SECONDS_PER_DAY = 24 * 60 * 60;
+
+function makeEngine(timeStepSeconds) {
+  return new Reactor_CSTR(makeReactorConfig({ reactor_type: 'CSTR', n_inlets: 1, timeStep: timeStepSeconds }));
+}
+
+test('engine stores timeStep in days, treating input as seconds', () => {
+  const eng = makeEngine(1);
+  assert.ok(Math.abs(eng.timeStep - 1 / SECONDS_PER_DAY) < 1e-15,
+    `engine.timeStep should be 1/86400 days for a 1-second config; got ${eng.timeStep}`);
+});
+
+test('engine timeStep scales linearly with config.timeStep (seconds in)', () => {
+  const a = makeEngine(1);
+  const b = makeEngine(10);
+  assert.ok(Math.abs(b.timeStep - 10 * a.timeStep) < 1e-15,
+    'engine.timeStep must scale linearly with config.timeStep; broke the seconds→days conversion');
+});
+
+test('schema default for timeStep matches the seconds convention', () => {
+  const path = require('node:path');
+  const gfRoot = path.dirname(require.resolve('generalFunctions'));
+  const schema = require(path.join(gfRoot, 'src/configs/reactor.json'));
+  assert.equal(schema.reactor.timeStep.rules.unit, 's',
+    'schema timeStep.unit must be "s" — engine treats input as seconds');
+  assert.equal(schema.reactor.timeStep.default, 1,
+    'schema timeStep.default must be 1 (1 second), matching reactor.html');
+});

test/helpers/factories.js

@@ -21,7 +21,7 @@ function makeUiConfig(overrides = {}) {
     X_S_init: 75,
     X_H_init: 30,
     X_STO_init: 0,
-    X_A_init: 0.001,
+    X_A_init: 200,
     X_TS_init: 125,
     timeStep: 1,
     enableLog: false,