feat(mgc): demand telemetry + movement gate (demand debounce)

- Movement gate: hold non-urgent demand while the group is 'working'
  (mid-ramp/sequencing) and flush it once 'ready', instead of aborting
  in-flight ramps on every incoming demand — which could freeze pumps at 0.
  Urgent demand (stop, mode/priority change, large step) still pre-empts.
- getMovementState()/_isUrgentDemand()/_maybeFlushPendingDemand() helpers.
- Demand telemetry: emit demandFlow (m³/h) and demandPct (0..100 of envelope)
  resolved by the last dispatch; omitted before the first demand (degraded).
- Capacity envelope now emitted in output flow unit (m³/h) not raw m³/s.
- Manifest + populated/degraded tests for the new outputs.

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

test/_output-manifest.md

@@ -26,10 +26,13 @@ Built by `src/io/output.js :: getOutput(mgc)`. Delta-compressed by
 | `scaling` | `mgc.scaling` | string ∈ {`absolute`, `normalized`} or undefined | commands.basic.test.js | dashboard-fanout (undefined → raw-rows shows '—') |
 | `absDistFromPeak` | `groupEfficiency.calcDistanceFromPeak` (specificClass.js:132) | number ≥ 0 (η-points) | bep-distance-demand-sweep, group-bep-cascade, groupEfficiency.basic | groupEfficiency.basic test 7 (undefined when current = null) |
 | `relDistFromPeak` | `groupEfficiency.calcRelativeDistanceFromPeak` | number ∈ [0,1] **OR `undefined`** for degenerate (homogeneous pumps) | bep-distance-demand-sweep, group-bep-cascade | groupEfficiency.basic tests 5/6/7 (undefined cases), dashboard-fanout test 11 (undefined → '—' display) |
-| `flowCapacityMax` | `mgc.dynamicTotals.flow.max` (totalsCalculator) | number m³/s ≥ 0 | totalsCalculator.basic, dashboard-fanout (post-setup) | absent until first equalize; dashboard-fanout (state A) |
-| `flowCapacityMin` | `mgc.dynamicTotals.flow.min` | number m³/s ≥ 0 | totalsCalculator.basic | same as above |
+| `flowCapacityMax` | `mgc.dynamicTotals.flow.max` (totalsCalculator), **converted to `unitPolicy.output.flow` (m³/h)** in output.js:62 | number m³/h ≥ 0; `0` when envelope unresolved (Infinity/NaN) | totalsCalculator.basic, dashboard-fanout (post-setup), demand-telemetry.basic | absent until first equalize; dashboard-fanout (state A); demand-telemetry (Infinity → 0) |
+| `flowCapacityMin` | `mgc.dynamicTotals.flow.min`, **converted to output flow unit (m³/h)** | number m³/h ≥ 0; `0` when unresolved | totalsCalculator.basic, demand-telemetry.basic | same as above |
+| `demandFlow` | `mgc._lastDemand.clamped` (set in `_runDispatch`, output.js:62) | number, canonical m³/s clamped to envelope, converted to `unitPolicy.output.flow` | demand-telemetry.basic (populated) | demand-telemetry.basic (absent before first demand); turnOff → 0 |
+| `demandPct` | derived `(clamped − flow.min)/(flow.max − flow.min)·100` (output.js:62) | number ∈ [0,100], `0` when capacity span ≤ 0 | demand-telemetry.basic (populated) | demand-telemetry.basic (absent before first demand) |
 | `machineCount` | `Object.keys(mgc.machines).length` | integer ≥ 0 | demand-cycle-walkthrough, ncog-distribution | n/a — always reflects current registration count |
 | `machineCountActive` | filtered count excluding `off`/`maintenance` states | integer ≥ 0 | demand-cycle-walkthrough, ncog-distribution | dashboard-fanout (state A: 0 active) |
+| `movementState` | `mgc.getMovementState()` (specificClass) — `'working'` while any child is ramping/sequencing or the executor has pending commands, else `'ready'` | string `'working'`\|`'ready'`, never null | movement-gate.basic (working: accelerating/warmingup/delayedMove/moveTimeLeft/executor-pending) | movement-gate.basic (ready: no machines, all settled) |
 
 ### Conditional pressure-header fields (emitted only when equalize resolved a positive ΔP)