governance + unit-self-describing demand + dashboard fixes

Two governance items from the 2026-05-14 quality review:
- test/_output-manifest.md enumerates every Port 0/1/2 key MGC emits, its
  source, type, range, and which tests cover it in populated/degraded states
  (per .claude/rules/output-coverage.md).
- src/control/strategies.js extracts computeEqualFlowDistribution as a pure
  function so the equal-flow algorithm is testable without an MGC fixture.
  test/basic/equalFlowDistribution.basic.test.js (6 tests) covers all three
  demand branches and pins the legacy quirk where the default branch counts
  active machines but iterates priority-ordered first-N (documented in the
  test so the future cleanup is a deliberate change).

Plus rolled-up session work that landed alongside:
- set.demand is now unit-self-describing ({value, unit:'m3/h'|'l/s'|'%'|...}
  or bare number = %); setScaling/scaling.current removed from MGC, commands,
  editor (mgc.html), specificClass.
- _optimalControl + equalFlowControl now compute eta = (Q*dP)/P_shaft rather
  than Q/P, keeping the metric in the same scale as each child's cog.
- groupEfficiency.calcRelativeDistanceFromPeak returns undefined (was 1) when
  pumps are homogeneous (|max-min| < 1e-9). Dashboard treats undefined as
  '-' instead of showing a misleading 100% / 0% reading.
- examples/02-Dashboard.json: auto-init inject so the dashboard populates at
  deploy, NCog formatter normalizes the SUM emitted by MGC by
  machineCountActive, Q-H fanout trims the flat-Q tail so the H axis isn't
  stretched to 40m by curve-envelope clamp points, num/pct treat null AND
  undefined as no-data (closes the +null === 0 trap).
- new test/integration/dashboard-fanout.integration.test.js (17 tests),
  bep-distance-demand-sweep.integration.test.js (3 tests),
  group-bep-cascade.integration.test.js -- total suite now 108/108 green.
- .gitignore: wiki/test.gif (143 MB screen recording, kept locally only).

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

src/commands/index.js

@@ -15,13 +15,6 @@ module.exports = [
     description: 'Switch the machine group between auto / manual modes.',
     handler: handlers.setMode,
   },
-  {
-    topic: 'set.scaling',
-    aliases: ['setScaling'],
-    payloadSchema: { type: 'string' },
-    description: 'Select the group scaling strategy.',
-    handler: handlers.setScaling,
-  },
   {
     topic: 'child.register',
     aliases: ['registerChild'],
@@ -33,10 +26,13 @@ module.exports = [
   {
     topic: 'set.demand',
     aliases: ['Qd'],
-    // any: number or numeric string — handler runs parseFloat.
+    // payload is either a bare number (interpreted as %) or
+    // { value: number, unit: '%' | 'm3/h' | 'l/s' | 'm3/s' | ... }.
+    // No `units` descriptor — the handler resolves the unit explicitly so
+    // commandRegistry._normaliseUnits doesn't pre-convert a percentage into
+    // a flow rate. Negative value is the operator stop-all signal.
     payloadSchema: { type: 'any' },
-    units: { measure: 'volumeFlowRate', default: 'm3/h' },
-    description: 'Operator demand setpoint dispatched to the child machines.',
+    description: 'Operator demand setpoint. Bare number = %; {value, unit} for absolute flow units. Negative = stop all.',
     handler: handlers.setDemand,
   },
 ];