feat(pumpingStation schema): add holdLevel + deadZoneKeepAlivePercent; slim npm pack

Schema:
- holdLevel (optional, default null → equals startLevel): 0 % ramp foot for
  the levelbased curve. When raised above startLevel, pumps engage at
  startLevel but hold at MGC flow.min across [startLevel, holdLevel] before
  the ramp begins.
- deadZoneKeepAlivePercent (default 1): percent emitted across the
  [stopLevel, startLevel] falling-edge keep-alive band.
- Refreshed startLevel / stopLevel descriptions: hysteresis is no longer
  coupled to inflowLevel (was misleading).

Packaging:
- Add .npmignore mirroring .gitignore plus the dev-only trees (test/,
  wiki/, scripts/, .claude/, …) so npm pack doesn't ship the doc set.
- Extend .gitignore with the standard dev-artifact deny list so both
  files share the same baseline.

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

.gitignore

@@ -1,5 +1,14 @@
+# Repo dev artifacts. Mirrors the deny list in .npmignore so the two stay
+# in sync — anything that shouldn't be committed AND shouldn't ship in the
+# npm tarball goes in both files.
 node_modules/
 
 # Local stub generated by `npm install` in the submodule directory.
 # generalFunctions has no production deps of its own.
 package-lock.json
+
+*.tgz
+.env
+.env.*
+.DS_Store
+npm-debug.log*

.npmignore

@@ -0,0 +1,28 @@
+# === Mirrors .gitignore — items below this block are also excluded from
+#     the npm tarball. Kept here verbatim so npm pack doesn't fall back to
+#     the .gitignore inheritance (silent + surprising). ===
+node_modules/
+package-lock.json
+*.tgz
+.env
+.env.*
+.DS_Store
+npm-debug.log*
+
+# === Dev-only content the npm tarball doesn't need ===
+# Tests + their harness — consumers load index.js, not the test tree.
+test/
+*.test.js
+
+# Wiki / docs — useful in the repo, big in the pack.
+wiki/
+
+# One-off maintenance tooling (wiki generator, etc.) not used at runtime.
+scripts/
+
+# Project memory + IDE configs.
+.claude/
+.codex/
+.repo-mem/
+CLAUDE.md
+CLAUDE.local.md

src/configs/pumpingStation.json

@@ -498,7 +498,7 @@
                 "rules": {
                     "type": "number",
                     "min": 0,
-                    "description": "Pump-on threshold (engagement edge for stopLevel hysteresis). Demand stays at 0 % between startLevel and inflowLevel — the ramp foot is inflowLevel, not startLevel. The ramp itself scales 0 → 100 % across [inflowLevel, maxLevel]. When enableShiftedRamp is on, startLevel also serves as the bottom of the held-then-ramp curve during draining."
+                    "description": "Pump-on threshold (rising-edge engagement). Pumps stay off below startLevel until level rises through it; once engaged they remain on until level drops through stopLevel (falling-edge). Also serves as the bottom of the held-then-ramp curve during draining when enableShiftedRamp is on. Independent of basin geometry: NOT clamped against inflowLevel."
                 }
             },
             "stopLevel": {
@@ -507,7 +507,25 @@
                     "type": "number",
                     "nullable": true,
                     "min": 0,
-                    "description": "Optional pump-off threshold. When set, PS sends an explicit turnOffAllMachines command to MGC the moment level drops below stopLevel. Independent of the ramp scaling — does NOT shift where the ramp starts. Pair with a startLevel above stopLevel to get hysteresis (pumps engage at startLevel rising, disengage at stopLevel falling). Must be ≥ minLevel and ≤ startLevel. NOTE: schema default stays null so omitting stopLevel keeps the hysteresis inactive (matching levelBased.js); the editor HTML provides a realistic 0.5 m default for drag-in UX."
+                    "description": "Optional pump-off threshold. When set, PS sends an explicit turnOffAllMachines command to MGC the moment level drops below stopLevel. Does NOT shape the ramp. Pair with a startLevel above stopLevel to get hysteresis (engage at startLevel rising, disengage at stopLevel falling). Must be ≥ minLevel and ≤ startLevel. NOTE: schema default stays null so omitting stopLevel keeps the hysteresis inactive; the editor HTML provides a realistic 0.5 m default for drag-in UX."
+                }
+            },
+            "holdLevel": {
+                "default": null,
+                "rules": {
+                    "type": "number",
+                    "nullable": true,
+                    "min": 0,
+                    "description": "Optional `0 %` ramp foot. When set, pumps engage at startLevel but hold at 0 % (= flow.min via MGC) across [startLevel, holdLevel], then ramp 0 → 100 % across [holdLevel, maxLevel]. Default null → equals startLevel, i.e. no hold band and the ramp starts immediately at startLevel. Must satisfy startLevel ≤ holdLevel ≤ maxLevel."
+                }
+            },
+            "deadZoneKeepAlivePercent": {
+                "default": 1,
+                "rules": {
+                    "type": "number",
+                    "min": 0,
+                    "max": 100,
+                    "description": "Percent emitted to MGC across the falling-edge keep-alive band [stopLevel, startLevel] (i.e. once engaged, while draining back below startLevel but still above stopLevel). 0 maps to flow.min; the 1 % default sits just above min so MGC keeps at least one pump rotating instead of resting at the absolute minimum."
                 }
             },
             "maxLevel": {