Merge origin/basin-docs-update: per-mode SVG + stopLevel hysteresis + shifted ramp

Reconciles the 7-commit basin-docs-update feature branch (which never
landed on main before the platform refactor) with the post-refactor
architecture on development. Each basin-docs feature ported into the
relevant concern module:

  control/levelBased.js
    - stopLevel Schmitt-trigger + dead-band keep-alive
    - Shifted ramp (arm % → hold @ 100% → ramp down to shiftLevel)
    - Linear vs log up-curve (curveType + logCurveFactor)

  measurement/flowAggregator.js
    - Predicted-volume overflow clamp + spill flow stream
    - Cumulative overflowVolume + underflowVolume
    - Hard floor at 0 + dry-run-on-transition handling

  basin/thresholdValidator.js
    - computeSafetyPoints exposes dryRunLevel + highVolumeSafetyLevel
    - startLevel ≤ inflowLevel invariant added

  measurement/calibration.js + commands/
    - Manual q_out path (set.outflow / q_out alias)

  safety/safetyController.js
    - Accepts both legacy + new high-volume threshold names

UI:
  pumpingStation.html — restored the side-panel + SVG mode-preview block,
  added defaults for stopLevel/shiftLevel/shiftArmPercent/levelCurveType/
  logCurveFactor/enableShiftedRamp.
  src/editor/* — basin-docs' 7-file modular editor (replaces single
  src/editor.js, which is deleted).
  pumpingStation.js — admin endpoint serves editor/:file.

Tests: 130/130 pass (125 basic + 5 integration). Two basin-docs test
files added: nodeClass-config.test.js, basic-dashboard-flow.test.js,
shifted-ramp-end-to-end.test.js. One pre-refactor control-levelBased
test adapted to match basin-docs canonical "no-shutdown in dead zone"
behaviour.

Human-review items (see commit context):
  - rampFoot = inflowLevel (matches basin-docs test); basin-docs source
    used rampFoot = startLevel. Domain owner: confirm intent.
  - Naming kept dual (overfillLevel + highVolumeSafetyLevel).

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

src/measurement/calibration.js

@@ -73,8 +73,19 @@ function setManualInflow(ctx, value, timestamp = Date.now(), unit = 'm3/s') {
     .value(num, timestamp, unit);
 }
 
+// Manual outflow injection mirroring setManualInflow — basin-docs adds this
+// for the dashboard's q_out topic so tests can drive a drain stroke without
+// instantiating a real pump.
+function setManualOutflow(ctx, value, timestamp = Date.now(), unit = 'm3/s') {
+  if (!ctx?.measurements) throw new Error('setManualOutflow: ctx.measurements required');
+  const num = Number(value);
+  ctx.measurements.type('flow').variant('predicted').position('out').child('manual-qout')
+    .value(num, timestamp, unit);
+}
+
 module.exports = {
   calibratePredictedVolume,
   calibratePredictedLevel,
   setManualInflow,
+  setManualOutflow,
 };