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 },
@@ -267,6 +267,7 @@
         <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="frost">frost</option>
       <option value="json">json</option>
             <option value="csv">csv</option>
         </select>