Docs + simulations refresh; align spill-flow keys with new position

- wiki/functional-description.md: rename Overfill Protection → High-volume
  Safety; tighten basin-ordering chain; relocate level-based mode
  diagrams under wiki/diagrams/modes/level-based/; document the new
  flow.predicted.overflow.default position (replaces the previous
  child='overflow' under position 'out'); add underflowVolume +
  predictedUnderflowVolume entries.
- wiki/modes/{levelbased,powerbased}.md: paragraph cleanups.
- wiki/diagrams: move level-linear basin diagram under modes/level-based/
  alongside a new level-log variant.
- simulations/run.js: add max_demand_gt expectation.
- simulations/scenarios/*: minor fixture updates.
- test/basic/nodeClass-config.test.js: new config-shape coverage.

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

simulations/README.md

@@ -49,6 +49,7 @@ module.exports = {
 | `max_level_bounded` | max level across the run must be `≤ value` |
 | `min_level_bounded` | min level across the run must be `≥ value` |
 | `max_demand_bounded` | max percControl must be `≤ value` |
+| `max_demand_gt` | max percControl must be `> value` |
 | `safety_trips_eq` | total ticks with `safetyActive` must equal `value` |
 | `safety_trips_gt` | total ticks with `safetyActive` must be `> value` |
 | `end_state_eq` | final record's `field` must equal `value` |