Fix jumping field order, tidy labels/units on Dashboard field list

The unordered plant_asset_latest query could return rows in a different
order after every MQTT upsert, making the field list under each asset card
appear to shuffle. Added ORDER BY, plus a curated label/unit/order table
for the known water-softener fields (Salt Level 42%, Tank A Capacity
1850 L, Regeneration Active Yes/No, ...) with a title-case + alphabetical
fallback for anything not yet mapped.

backend/src/routes/status.js

@@ -14,9 +14,13 @@ export async function statusRoutes(app) {
       SELECT * FROM plant_assets WHERE active = TRUE ORDER BY asset_type, name
     `)
 
+    // ORDER BY matters here — without it, Postgres can return this heavily-
+    // upserted table's rows in a different order after every MQTT message,
+    // which made the Dashboard's field list appear to shuffle on refresh.
     const { rows: latest } = await pool.query(`
       SELECT asset_id, field_key, value_numeric, value_text, updated_at
       FROM plant_asset_latest
+      ORDER BY asset_id, field_key
     `)
     const latestByAsset = new Map()
     for (const l of latest) {

frontend/src/pages/Dashboard.tsx

@@ -1,20 +1,57 @@
 import { useEffect, useState, useCallback } from 'react'
 import { AlertTriangle, WifiOff } from 'lucide-react'
 import { fetchStatus } from '../api'
-import type { AssetStatus, AssetType } from '../types'
+import type { AssetStatus, AssetType, TelemetryField } from '../types'
 import { ASSET_TYPES, ASSET_TYPE_LABELS } from '../types'
 import WaterSoftenerDiagram from '../components/WaterSoftenerDiagram'
 
 const POLL_MS = 30000
 
-function fieldLabel(key: string): string {
-  return key.replace(/_/g, ' ')
+// Curated presentation for known MQTT field_keys — proper label, unit, a
+// fixed display order, and whether the value is boolean-ish. Anything not
+// listed here (other asset types, fields not yet known) falls back to a
+// title-cased label and sorts alphabetically after all known fields, so the
+// list never breaks for an unmapped field, it just looks less polished.
+interface FieldMeta { label: string; order: number; unit?: string; boolean?: boolean }
+const FIELD_META: Record<string, FieldMeta> = {
+  salt_level_pct:    { label: 'Salt Level',         order: 1, unit: '%' },
+  salt_level_status: { label: 'Salt Status',        order: 2 },
+  tank_a_capacity_l: { label: 'Tank A Capacity',    order: 3, unit: 'L' },
+  tank_b_capacity_l: { label: 'Tank B Capacity',    order: 4, unit: 'L' },
+  tank_in_service:   { label: 'Tank In Service',    order: 5, boolean: true },
+  regen_active:      { label: 'Regeneration Active', order: 6, boolean: true },
 }
 
-function fieldValue(f: { value_numeric: string | null; value_text: string | null }): string {
+function titleCase(key: string): string {
+  return key.replace(/_/g, ' ').replace(/\b\w/g, c => c.toUpperCase())
+}
+
+function isTruthyField(f: TelemetryField): boolean {
+  if (f.value_numeric !== null) return Number(f.value_numeric) === 1
+  const t = (f.value_text || '').trim().toLowerCase()
+  return t === 'true' || t === 'on' || t === '1' || t === 'yes'
+}
+
+function fieldLabel(key: string): string {
+  return FIELD_META[key]?.label ?? titleCase(key)
+}
+
+function fieldValue(f: TelemetryField): string {
+  const meta = FIELD_META[f.field_key]
+  if (meta?.boolean) return isTruthyField(f) ? 'Yes' : 'No'
   if (f.value_text !== null && f.value_text !== '' && isNaN(Number(f.value_text))) return f.value_text
-  if (f.value_numeric !== null) return f.value_numeric
-  return f.value_text ?? '—'
+  if (f.value_numeric === null) return f.value_text ?? '—'
+  const rounded = Math.round(Number(f.value_numeric) * 100) / 100
+  if (!meta?.unit) return String(rounded)
+  return meta.unit === '%' ? `${rounded}%` : `${rounded} ${meta.unit}`
+}
+
+function sortedFields(latest: TelemetryField[]): TelemetryField[] {
+  return [...latest].sort((a, b) => {
+    const oa = FIELD_META[a.field_key]?.order ?? 999
+    const ob = FIELD_META[b.field_key]?.order ?? 999
+    return oa !== ob ? oa - ob : a.field_key.localeCompare(b.field_key)
+  })
 }
 
 function AssetCard({ asset }: { asset: AssetStatus }) {
@@ -38,7 +75,7 @@ function AssetCard({ asset }: { asset: AssetStatus }) {
         <div className="muted" style={{ fontSize: 12.5 }}>No telemetry received yet.</div>
       ) : (
         <div className="asset-field-list">
-          {asset.latest.map(f => (
+          {sortedFields(asset.latest).map(f => (
             <div key={f.field_key} className="asset-field-row">
               <span className="asset-field-key">{fieldLabel(f.field_key)}</span>
               <span className="asset-field-value">{fieldValue(f)}</span>