Propagate threshold rename; point platform manual at pumpingStation wiki

Follows pumpingStation@a218945 + generalFunctions@4252292 rename:

- Bump pumpingStation and generalFunctions submodule pointers.
- Update examples/pumpingstation-3pumps-dashboard/ (build_flow.py,
  flow.json, README.md) to use the new threshold names. Collapsed
  minFlowLevel into startLevel; reshuffled order to match the basin
  bottom-to-top: minLevel, startLevel, maxLevel.
- wiki/manuals/README.md: drop the stale pumpingStation.md line and
  point readers at pumpingStation/wiki instead (docs have moved into
  the node's own repo).

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

examples/pumpingstation-3pumps-dashboard/README.md

@@ -91,7 +91,7 @@ The Emergency Stop button always works regardless of mode and uses the new inter
 
 ## Notable design choices
 
-- **PS is in `manual` control mode** (`controlMode: "manual"`). The default `levelbased` mode would auto-shut all pumps as soon as basin level dips below `stopLevel` (1 m default), which masks the demo. Manual = observation only.
+- **PS is in `manual` control mode** (`controlMode: "manual"`). The default `levelbased` mode would auto-shut all pumps as soon as basin level dips below `minLevel` (1 m default), which masks the demo. Manual = observation only.
 - **PS safety guards (dry-run / overfill) disabled.** With no real inflow the basin will frequently look "empty" — that's expected for a demo, not a fault. In production you'd configure a real `q_in` source and leave safeties on.
 - **MGC scaling = `absolute`, mode = `optimalcontrol`.** Set via inject at deploy. Demand in m³/h, BEP-driven distribution.
 - **demand_router gates Qd ≤ 0.** A demand of 0 would shut every running pump (via MGC.turnOffAllMachines). Use the explicit Stop All button to actually take pumps down.