feat(output): alwaysEmit fields, drop undefined/empty Influx tags, time-based movement re-basing

- OutputUtils: new `alwaysEmit` option exempts named fields from delta
  compression so steady-state values (e.g. ctrl) trace continuously.
- flattenTags now drops null/undefined/empty-string tag values, fixing
  literal `category="undefined"` tags that split every Grafana series in two.
- BaseNodeAdapter wires `static alwaysEmitFields` from the subclass.
- movementManager: track position by elapsed wall-time and capture partial
  progress on abort, so a fast-re-commanding parent can't freeze an actuator
  at its start position.
- Tests for the above.

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

src/helper/outputUtils.js

@@ -2,8 +2,16 @@ const { getFormatter } = require('./formatters');
 
 //this class will handle the output events for the node red node
 class OutputUtils {
-  constructor() {
+  // `options.alwaysEmit` is an optional list of field keys that bypass delta
+  // compression: they are re-emitted on every tick even when unchanged. Use it
+  // sparingly for slowly-varying values that must still trace as a continuous
+  // line downstream (e.g. a pump's realized control position `ctrl`, which sits
+  // constant in steady state and otherwise produces ~1 point per long stretch —
+  // invisible in a Grafana timeseries with createEmpty:false). Defaults to none,
+  // so existing nodes keep pure delta-compression behaviour.
+  constructor(options = {}) {
     this.output = {};
+    this.alwaysEmit = new Set(options.alwaysEmit || []);
   }
 
   checkForChanges(output, format) {
@@ -13,7 +21,9 @@ class OutputUtils {
     this.output[format] = this.output[format] || {};
     const changedFields = {};
     for (const key in output) {
-      if (Object.prototype.hasOwnProperty.call(output, key) && output[key] !== this.output[format][key]) {
+      if (!Object.prototype.hasOwnProperty.call(output, key)) continue;
+      const forced = this.alwaysEmit.has(key) && output[key] !== undefined;
+      if (forced || output[key] !== this.output[format][key]) {
         let value = output[key];
         // For fields: if the value is an object (and not a Date), stringify it.
         if (value !== null && typeof value === 'object' && !(value instanceof Date)) {
@@ -79,7 +89,13 @@ class OutputUtils {
     for (const key in obj) {
       if (Object.prototype.hasOwnProperty.call(obj, key)) {
         const value = obj[key];
-        if (value !== null && typeof value === 'object' && !(value instanceof Date)) {
+        // Skip tags that carry no information. When a config field is unset,
+        // extractRelevantConfig hands us `undefined`; stringifying that wrote
+        // literal `category="undefined"` / `geoLocation="undefined"` tags that
+        // clutter every Grafana legend and needlessly inflate tag cardinality.
+        // Drop null / undefined / empty-string before they reach InfluxDB.
+        if (value === null || value === undefined || value === '') continue;
+        if (typeof value === 'object' && !(value instanceof Date)) {
           // Recursively flatten the nested object.
           const flatChild = this.flattenTags(value);
           for (const childKey in flatChild) {