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/integration/structure-examples.integration.test.js

@@ -9,14 +9,16 @@ function loadJson(file) {
   return JSON.parse(fs.readFileSync(path.join(dir, file), 'utf8'));
 }
 
+const FLOW_FILES = ['01-Basic.json', '02-Dashboard.json'];
+
 test('examples package exists for machineGroupControl', () => {
-  for (const file of ['README.md', 'basic.flow.json', 'integration.flow.json', 'edge.flow.json']) {
+  for (const file of ['README.md', ...FLOW_FILES]) {
     assert.equal(fs.existsSync(path.join(dir, file)), true, file + ' missing');
   }
 });
 
 test('example flows are parseable arrays for machineGroupControl', () => {
-  for (const file of ['basic.flow.json', 'integration.flow.json', 'edge.flow.json']) {
+  for (const file of FLOW_FILES) {
     const parsed = loadJson(file);
     assert.equal(Array.isArray(parsed), true);
   }