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>

test/basic/groupEfficiency.basic.test.js

@@ -53,14 +53,33 @@ test('calcDistanceBEP returns both abs + rel', () => {
     assert.ok(Math.abs(relDistFromPeak - expectedRel) < 1e-9);
 });
 
-test('calcRelativeDistanceFromPeak returns 1 when max === min (degenerate)', () => {
+test('calcRelativeDistanceFromPeak returns undefined when max === min (degenerate)', () => {
+    // For homogeneous pump groups (all cogs equal), the [max..min] band
+    // collapses and the metric is mathematically undefined. Return undefined
+    // so the dashboard displays "—" instead of a misleading 0% / 100%.
     const ge = makeGE();
-    assert.equal(ge.calcRelativeDistanceFromPeak(0.85, 0.8, 0.8), 1);
+    assert.equal(ge.calcRelativeDistanceFromPeak(0.85, 0.8, 0.8), undefined);
 });
 
-test('calcRelativeDistanceFromPeak returns 1 when current is null', () => {
+test('calcRelativeDistanceFromPeak returns undefined when max ≈ min within epsilon', () => {
+    // Float noise from identical pumps: max-min might be 1e-12 rather than 0.
+    // Must still report undefined — the interpolation extrapolates wildly here.
     const ge = makeGE();
-    assert.equal(ge.calcRelativeDistanceFromPeak(null, 0.92, 0.7), 1);
+    assert.equal(ge.calcRelativeDistanceFromPeak(0.85, 0.211264, 0.211263999), undefined);
+});
+
+test('calcRelativeDistanceFromPeak returns undefined when current is null', () => {
+    const ge = makeGE();
+    assert.equal(ge.calcRelativeDistanceFromPeak(null, 0.92, 0.7), undefined);
+});
+
+test('calcDistanceBEP propagates undefined relDist for degenerate input', () => {
+    // Regression: if currentEff is finite, absDist is still computed (it's
+    // just |current - peak|), but relDist must be undefined for degenerate.
+    const ge = makeGE();
+    const { absDistFromPeak, relDistFromPeak } = ge.calcDistanceBEP(0.206, 0.211, 0.211);
+    assert.ok(Math.abs(absDistFromPeak - 0.005) < 1e-9);
+    assert.equal(relDistFromPeak, undefined);
 });
 
 test('calcGroupEfficiency handles a single machine', () => {